From 3cfcca5fc6e1e9aa22b69edb8daa5c0735d05d10 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 16 Dec 2025 11:50:08 +0300
Subject: [PATCH 01/39] f$deflate_init

---
 runtime-light/stdlib/zlib/deflatecontext.h   |  21 ++++
 runtime-light/stdlib/zlib/zlib-functions.cpp | 110 +++++++++++++++++++
 runtime-light/stdlib/zlib/zlib-functions.h   |   6 +
 3 files changed, 137 insertions(+)
 create mode 100644 runtime-light/stdlib/zlib/deflatecontext.h

diff --git a/runtime-light/stdlib/zlib/deflatecontext.h b/runtime-light/stdlib/zlib/deflatecontext.h
new file mode 100644
index 0000000000..d085787aee
--- /dev/null
+++ b/runtime-light/stdlib/zlib/deflatecontext.h
@@ -0,0 +1,21 @@
+// Compiler for PHP (aka KPHP)
+// Copyright (c) 2024 LLC «V Kontakte»
+// Distributed under the GPL v3 License, see LICENSE.notice.txt
+
+#pragma once
+
+#include "zlib/zlib.h"
+
+#include "runtime-common/core/class-instance/refcountable-php-classes.h"
+#include "runtime-common/stdlib/visitors/dummy-visitor-methods.h"
+
+struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, private DummyVisitorMethods {
+  C$DeflateContext() = default;
+  using DummyVisitorMethods::accept;
+
+  ~C$DeflateContext() {
+    deflateEnd(&stream);
+  }
+
+  z_stream stream{};
+};
diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index d0783e0bee..a8969aa141 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -15,6 +15,7 @@
 #include "zlib/zlib.h"
 
 #include "common/containers/final_action.h"
+#include "runtime-common/core/allocator/script-malloc-interface.h"
 #include "runtime-common/core/runtime-core.h"
 #include "runtime-light/stdlib/diagnostics/logs.h"
 #include "runtime-light/stdlib/string/string-state.h"
@@ -36,6 +37,21 @@ voidpf zlib_static_alloc(voidpf opaque, uInt items, uInt size) noexcept {
 
 void zlib_static_free([[maybe_unused]] voidpf opaque, [[maybe_unused]] voidpf address) noexcept {}
 
+voidpf zlib_dynamic_alloc([[maybe_unused]] voidpf opaque, uInt items, uInt size) noexcept {
+  auto* mem{kphp::memory::script::calloc(items, size)};
+  if (mem == nullptr) [[unlikely]] {
+    kphp::log::warning("zlib dynamic alloc: can't allocate {} bytes", items * size);
+  }
+  return mem;
+}
+
+void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept {
+  if (address == nullptr) [[unlikely]] {
+    return;
+  }
+  kphp::memory::script::free(address);
+}
+
 } // namespace
 
 namespace kphp::zlib {
@@ -115,3 +131,97 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 }
 
 } // namespace kphp::zlib
+
+class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
+  int32_t level{-1};
+  int32_t memory{8};
+  int32_t window{15};
+  auto strategy{Z_DEFAULT_STRATEGY};
+  auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
+    const mixed& value = option.get_value();
+    if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
+      dst = value.as_int();
+      return true;
+    } else {
+      kphp::log::warning("deflate_init() : option {} should be number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
+      return false;
+    }
+  }};
+  switch (encoding) {
+  case kphp::zlib::ENCODING_RAW:
+  case kphp::zlib::ENCODING_DEFLATE:
+  case kphp::zlib::ENCODING_GZIP:
+    break;
+  default:
+    kphp::log::warning("deflate_init() : encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
+    return {};
+  }
+  for (const auto& option : options) {
+    mixed value;
+    if (!option.is_string_key()) {
+      kphp::log::warning("deflate_init() : unsupported option");
+      return {};
+    }
+    if (option.get_string_key() == string("level")) {
+      if (!extract_int_option(-1, 9, option, level)) {
+        return {};
+      }
+    } else if (option.get_string_key() == string("memory")) {
+      if (!extract_int_option(1, 9, option, memory)) {
+        return {};
+      }
+    } else if (option.get_string_key() == string("window")) {
+      if (!extract_int_option(8, 15, option, window)) {
+        return {};
+      }
+    } else if (option.get_string_key() == string("strategy")) {
+      value = option.get_value();
+      if (value.is_int()) {
+        switch (value.as_int()) {
+        case Z_FILTERED:
+        case Z_HUFFMAN_ONLY:
+        case Z_RLE:
+        case Z_FIXED:
+        case Z_DEFAULT_STRATEGY:
+          strategy = value.as_int();
+          break;
+        default:
+          kphp::log::warning(
+              "deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+          return {};
+        }
+      } else {
+        kphp::log::warning("deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+        return {};
+      }
+    } else if (option.get_string_key() == string("dictionary")) {
+      kphp::log::warning("deflate_init() : option dictionary isn't supported yet");
+      return {};
+    } else {
+      kphp::log::warning("deflate_init() : unknown option name \"{}\"", option.get_string_key().c_str());
+      return {};
+    }
+  }
+
+  class_instance<C$DeflateContext> context;
+  context.alloc();
+
+  z_stream* stream{std::addressof(context.get()->stream)};
+  stream->zalloc = zlib_dynamic_alloc;
+  stream->zfree = zlib_dynamic_free;
+  stream->opaque = nullptr;
+
+  if (encoding < 0) {
+    encoding += 15 - window;
+  } else {
+    encoding -= 15 - window;
+  }
+
+  auto err{deflateInit2(stream, level, Z_DEFLATED, encoding, memory, strategy)};
+  if (err != Z_OK) {
+    kphp::log::warning("deflate_init() : zlib error {}", zError(err));
+    context.destroy();
+    return {};
+  }
+  return context;
+}
diff --git a/runtime-light/stdlib/zlib/zlib-functions.h b/runtime-light/stdlib/zlib/zlib-functions.h
index 968a141f36..ed7514f2f1 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.h
+++ b/runtime-light/stdlib/zlib/zlib-functions.h
@@ -10,6 +10,7 @@
 #include <span>
 
 #include "runtime-common/core/runtime-core.h"
+#include "runtime-light/stdlib/zlib/deflatecontext.h"
 
 namespace kphp::zlib {
 
@@ -53,3 +54,8 @@ inline string f$gzdeflate(const string& data, int64_t level = kphp::zlib::MIN_CO
 inline string f$gzinflate(const string& data) noexcept {
   return kphp::zlib::decode({data.c_str(), static_cast<size_t>(data.size())}, kphp::zlib::ENCODING_RAW).value_or(string{});
 }
+
+class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options = {}) noexcept;
+
+Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context, const string& data, int64_t flush_type = Z_SYNC_FLUSH) noexcept;
+

From a276c4798376742bc37b80b03e931084ed5a9056 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 16 Dec 2025 13:22:51 +0300
Subject: [PATCH 02/39] f$deflate_add & tests

---
 .../kphp-light/stdlib/zlib-functions.txt      | 22 +++----
 runtime-light/stdlib/zlib/zlib-functions.cpp  | 64 +++++++++++++++++--
 tests/phpt/pk/016_gzip.php                    |  2 +-
 3 files changed, 69 insertions(+), 19 deletions(-)

diff --git a/builtin-functions/kphp-light/stdlib/zlib-functions.txt b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
index c340c48be7..68d5e2fdff 100644
--- a/builtin-functions/kphp-light/stdlib/zlib-functions.txt
+++ b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
@@ -18,6 +18,15 @@ function gzdeflate ($str ::: string, $level ::: int = -1) ::: string;
 
 function gzinflate ($str ::: string) ::: string;
 
+function deflate_init(int $encoding, array $options = []) ::: ?DeflateContext;
+
+function deflate_add(DeflateContext $context, string $data, int $flush_mode = ZLIB_SYNC_FLUSH) ::: string | false;
+
+final class DeflateContext {
+    private function __construct() ::: DeflateContext;
+}
+
+
 // ===== UNSUPPORTED =====
 
 /** @kphp-extern-func-info stub generation-required */
@@ -36,16 +45,3 @@ define('ZLIB_HUFFMAN_ONLY', 2);
 define('ZLIB_RLE', 3);
 define('ZLIB_FIXED', 4);
 define('ZLIB_DEFAULT_STRATEGY', 0);
-
-/** @kphp-generate-stub-class */
-final class DeflateContext {
-    /** @kphp-extern-func-info stub generation-required */
-    private function __construct() ::: DeflateContext;
-}
-
-// todo: deflate_init php signature has type array instead mixed
-/** @kphp-extern-func-info stub generation-required */
-function deflate_init(int $encoding, mixed $options = []) ::: ?DeflateContext;
-/** @kphp-extern-func-info stub generation-required */
-function deflate_add(DeflateContext $context, string $data, int $flush_mode = ZLIB_SYNC_FLUSH) ::: string | false;
-
diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index a8969aa141..7fdd868739 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -162,19 +162,19 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
       kphp::log::warning("deflate_init() : unsupported option");
       return {};
     }
-    if (option.get_string_key() == string("level")) {
+    if (option.get_string_key() == string{"level"}) {
       if (!extract_int_option(-1, 9, option, level)) {
         return {};
       }
-    } else if (option.get_string_key() == string("memory")) {
+    } else if (option.get_string_key() == string{"memory"}) {
       if (!extract_int_option(1, 9, option, memory)) {
         return {};
       }
-    } else if (option.get_string_key() == string("window")) {
+    } else if (option.get_string_key() == string{"window"}) {
       if (!extract_int_option(8, 15, option, window)) {
         return {};
       }
-    } else if (option.get_string_key() == string("strategy")) {
+    } else if (option.get_string_key() == string{"strategy"}) {
       value = option.get_value();
       if (value.is_int()) {
         switch (value.as_int()) {
@@ -194,7 +194,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
         kphp::log::warning("deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
         return {};
       }
-    } else if (option.get_string_key() == string("dictionary")) {
+    } else if (option.get_string_key() == string{"dictionary"}) {
       kphp::log::warning("deflate_init() : option dictionary isn't supported yet");
       return {};
     } else {
@@ -225,3 +225,57 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   }
   return context;
 }
+
+Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context, const string& data, int64_t flush_type) noexcept {
+  switch (flush_type) {
+  case Z_BLOCK:
+  case Z_NO_FLUSH:
+  case Z_PARTIAL_FLUSH:
+  case Z_SYNC_FLUSH:
+  case Z_FULL_FLUSH:
+  case Z_FINISH:
+    break;
+  default:
+    kphp::log::warning(
+        "deflate_add() : flush type should be one of ZLIB_NO_FLUSH, ZLIB_PARTIAL_FLUSH, ZLIB_SYNC_FLUSH, ZLIB_FULL_FLUSH, ZLIB_FINISH, ZLIB_BLOCK, ZLIB_TREES");
+    return {};
+  }
+
+  z_stream* stream{std::addressof(context.get()->stream)};
+  auto out_size{deflateBound(stream, data.size()) + 30};
+  out_size = out_size < 64 ? 64 : out_size;
+  string out{static_cast<string::size_type>(out_size), false};
+  stream->next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(data.c_str()));
+  stream->next_out = reinterpret_cast<Bytef*>(out.buffer());
+  stream->avail_in = data.size();
+  stream->avail_out = out_size;
+
+  auto status{Z_OK};
+  uint64_t buffer_used{};
+  do {
+    if (stream->avail_out == 0) {
+      out.reserve_at_least(out_size + 64);
+      out_size += 64;
+      stream->avail_out = 64;
+      stream->next_out = reinterpret_cast<Bytef*>(std::next(out.buffer(), buffer_used));
+    }
+    status = deflate(stream, flush_type);
+    buffer_used = out_size - stream->avail_out;
+  } while (status == Z_OK && stream->avail_out == 0);
+
+  std::ptrdiff_t len{};
+  switch (status) {
+  case Z_OK:
+    len = std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out);
+    out.shrink(len);
+    return out;
+  case Z_STREAM_END:
+    len = std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out);
+    deflateReset(stream);
+    out.shrink(len);
+    return out;
+  default:
+    kphp::log::warning("deflate_add() : zlib error {}", zError(status));
+    return {};
+  }
+}
diff --git a/tests/phpt/pk/016_gzip.php b/tests/phpt/pk/016_gzip.php
index 93e7c980a7..9032555ed8 100644
--- a/tests/phpt/pk/016_gzip.php
+++ b/tests/phpt/pk/016_gzip.php
@@ -1,4 +1,4 @@
-@ok k2_skip
+@ok
 <?php
 
 $x = "";

From 92ed7c45a33c979980b6d3ce8457e53c178f55b8 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 16 Dec 2025 13:34:19 +0300
Subject: [PATCH 03/39] format

---
 runtime-light/stdlib/zlib/zlib-functions.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.h b/runtime-light/stdlib/zlib/zlib-functions.h
index ed7514f2f1..d23dc1345f 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.h
+++ b/runtime-light/stdlib/zlib/zlib-functions.h
@@ -58,4 +58,3 @@ inline string f$gzinflate(const string& data) noexcept {
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options = {}) noexcept;
 
 Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context, const string& data, int64_t flush_type = Z_SYNC_FLUSH) noexcept;
-

From 0034e3b1480f5373bfa9c79a1c7fb040628653c6 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 12:37:17 +0300
Subject: [PATCH 04/39] noexcept

---
 runtime-light/stdlib/zlib/deflatecontext.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/deflatecontext.h b/runtime-light/stdlib/zlib/deflatecontext.h
index d085787aee..2f9e40b854 100644
--- a/runtime-light/stdlib/zlib/deflatecontext.h
+++ b/runtime-light/stdlib/zlib/deflatecontext.h
@@ -10,7 +10,7 @@
 #include "runtime-common/stdlib/visitors/dummy-visitor-methods.h"
 
 struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, private DummyVisitorMethods {
-  C$DeflateContext() = default;
+  C$DeflateContext() noexcept = default;
   using DummyVisitorMethods::accept;
 
   ~C$DeflateContext() {

From 9ec93d86dae0f2a6be6604074085ee35230010db Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 12:38:41 +0300
Subject: [PATCH 05/39] std::addressof

---
 runtime-light/stdlib/zlib/deflatecontext.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/deflatecontext.h b/runtime-light/stdlib/zlib/deflatecontext.h
index 2f9e40b854..5ea4f94a99 100644
--- a/runtime-light/stdlib/zlib/deflatecontext.h
+++ b/runtime-light/stdlib/zlib/deflatecontext.h
@@ -14,7 +14,7 @@ struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, pri
   using DummyVisitorMethods::accept;
 
   ~C$DeflateContext() {
-    deflateEnd(&stream);
+    deflateEnd(std::addressof(stream));
   }
 
   z_stream stream{};

From d94ed8921ca838cc2b2b61ede87a8582b05a9237 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 12:42:01 +0300
Subject: [PATCH 06/39] brace init

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 7fdd868739..fcfa10b906 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -138,7 +138,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   int32_t window{15};
   auto strategy{Z_DEFAULT_STRATEGY};
   auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
-    const mixed& value = option.get_value();
+    const mixed& value{option.get_value()};
     if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
       dst = value.as_int();
       return true;

From 53d5b08bb35361bc6636abab4f75af00848489ca Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 13:00:53 +0300
Subject: [PATCH 07/39] rewrite key comparing

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index fcfa10b906..fd478ee67b 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -162,19 +162,20 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
       kphp::log::warning("deflate_init() : unsupported option");
       return {};
     }
-    if (option.get_string_key() == string{"level"}) {
+    const auto& key = option.get_string_key();
+    if (std::string_view{key.c_str(), key.size()} == "level") {
       if (!extract_int_option(-1, 9, option, level)) {
         return {};
       }
-    } else if (option.get_string_key() == string{"memory"}) {
+    } else if (std::string_view{key.c_str(), key.size()} == "memory") {
       if (!extract_int_option(1, 9, option, memory)) {
         return {};
       }
-    } else if (option.get_string_key() == string{"window"}) {
+    } else if (std::string_view{key.c_str(), key.size()} == "window") {
       if (!extract_int_option(8, 15, option, window)) {
         return {};
       }
-    } else if (option.get_string_key() == string{"strategy"}) {
+    } else if (std::string_view{key.c_str(), key.size()} == "strategy") {
       value = option.get_value();
       if (value.is_int()) {
         switch (value.as_int()) {
@@ -194,7 +195,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
         kphp::log::warning("deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
         return {};
       }
-    } else if (option.get_string_key() == string{"dictionary"}) {
+    } else if (std::string_view{key.c_str(), key.size()} == "dictionary") {
       kphp::log::warning("deflate_init() : option dictionary isn't supported yet");
       return {};
     } else {

From 7452dd18afedad2445315b4eb7ce6bbc2e53c1ef Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 19:17:33 +0300
Subject: [PATCH 08/39] small fixes

---
 .../kphp-light/stdlib/zlib-functions.txt      | 28 +++++++++----------
 runtime-light/stdlib/zlib/zlib-functions.cpp  | 18 ++++++------
 2 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/builtin-functions/kphp-light/stdlib/zlib-functions.txt b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
index 68d5e2fdff..2121dc2f37 100644
--- a/builtin-functions/kphp-light/stdlib/zlib-functions.txt
+++ b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
@@ -6,6 +6,20 @@ define('ZLIB_ENCODING_RAW', -0x0f);
 define('ZLIB_ENCODING_DEFLATE', 0x0f);
 define('ZLIB_ENCODING_GZIP', 0x1f);
 
+define('ZLIB_NO_FLUSH', 0);
+define('ZLIB_PARTIAL_FLUSH', 1);
+define('ZLIB_SYNC_FLUSH', 2);
+define('ZLIB_FULL_FLUSH', 3);
+define('ZLIB_FINISH', 4);
+define('ZLIB_BLOCK', 5);
+define('ZLIB_TREES', 6);
+
+define('ZLIB_FILTERED', 1);
+define('ZLIB_HUFFMAN_ONLY', 2);
+define('ZLIB_RLE', 3);
+define('ZLIB_FIXED', 4);
+define('ZLIB_DEFAULT_STRATEGY', 0);
+
 function gzcompress ($str ::: string, $level ::: int = -1): string;
 
 function gzuncompress ($str ::: string): string;
@@ -31,17 +45,3 @@ final class DeflateContext {
 
 /** @kphp-extern-func-info stub generation-required */
 function md5_file ($s ::: string, $raw_output ::: bool = false) ::: string | false;
-
-define('ZLIB_NO_FLUSH', 0);
-define('ZLIB_PARTIAL_FLUSH', 1);
-define('ZLIB_SYNC_FLUSH', 2);
-define('ZLIB_FULL_FLUSH', 3);
-define('ZLIB_FINISH', 4);
-define('ZLIB_BLOCK', 5);
-define('ZLIB_TREES', 6);
-
-define('ZLIB_FILTERED', 1);
-define('ZLIB_HUFFMAN_ONLY', 2);
-define('ZLIB_RLE', 3);
-define('ZLIB_FIXED', 4);
-define('ZLIB_DEFAULT_STRATEGY', 0);
diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index fd478ee67b..3660aec0ff 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -153,13 +153,13 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   case kphp::zlib::ENCODING_GZIP:
     break;
   default:
-    kphp::log::warning("deflate_init() : encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
+    kphp::log::warning("encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
     return {};
   }
   for (const auto& option : options) {
     mixed value;
     if (!option.is_string_key()) {
-      kphp::log::warning("deflate_init() : unsupported option");
+      kphp::log::warning("unsupported option");
       return {};
     }
     const auto& key = option.get_string_key();
@@ -188,18 +188,18 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
           break;
         default:
           kphp::log::warning(
-              "deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+              "option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
           return {};
         }
       } else {
-        kphp::log::warning("deflate_init() : option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+        kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
         return {};
       }
     } else if (std::string_view{key.c_str(), key.size()} == "dictionary") {
-      kphp::log::warning("deflate_init() : option dictionary isn't supported yet");
+      kphp::log::warning("option dictionary isn't supported yet");
       return {};
     } else {
-      kphp::log::warning("deflate_init() : unknown option name \"{}\"", option.get_string_key().c_str());
+      kphp::log::warning("unknown option name \"{}\"", option.get_string_key().c_str());
       return {};
     }
   }
@@ -220,7 +220,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 
   auto err{deflateInit2(stream, level, Z_DEFLATED, encoding, memory, strategy)};
   if (err != Z_OK) {
-    kphp::log::warning("deflate_init() : zlib error {}", zError(err));
+    kphp::log::warning("zlib error {}", zError(err));
     context.destroy();
     return {};
   }
@@ -238,7 +238,7 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     break;
   default:
     kphp::log::warning(
-        "deflate_add() : flush type should be one of ZLIB_NO_FLUSH, ZLIB_PARTIAL_FLUSH, ZLIB_SYNC_FLUSH, ZLIB_FULL_FLUSH, ZLIB_FINISH, ZLIB_BLOCK, ZLIB_TREES");
+        "flush type should be one of ZLIB_NO_FLUSH, ZLIB_PARTIAL_FLUSH, ZLIB_SYNC_FLUSH, ZLIB_FULL_FLUSH, ZLIB_FINISH, ZLIB_BLOCK, ZLIB_TREES");
     return {};
   }
 
@@ -276,7 +276,7 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     out.shrink(len);
     return out;
   default:
-    kphp::log::warning("deflate_add() : zlib error {}", zError(status));
+    kphp::log::warning("zlib error {}", zError(status));
     return {};
   }
 }

From 9df0e8360da2ade257dfc284fbdc3bf95c92d754 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 19:19:36 +0300
Subject: [PATCH 09/39] constexpr

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 3660aec0ff..3ace06039c 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -137,7 +137,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   int32_t memory{8};
   int32_t window{15};
   auto strategy{Z_DEFAULT_STRATEGY};
-  auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
+  constexpr auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
     const mixed& value{option.get_value()};
     if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
       dst = value.as_int();

From a184c56b8d59c6dfaf6fad94ccebacd187ba8c34 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Thu, 18 Dec 2025 19:22:22 +0300
Subject: [PATCH 10/39] move statement to if

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 3ace06039c..e8e4aff085 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -89,8 +89,7 @@ std::optional<string> encode(std::span<const char> data, int64_t level, int64_t
   zstrm.avail_out = out_size_upper_bound;
   zstrm.next_out = reinterpret_cast<Bytef*>(runtime_ctx.static_SB.buffer());
 
-  const auto deflate_res{deflate(std::addressof(zstrm), Z_FINISH)};
-  if (deflate_res != Z_STREAM_END) [[unlikely]] {
+  if (const auto deflate_res{deflate(std::addressof(zstrm), Z_FINISH)}; deflate_res != Z_STREAM_END) [[unlikely]] {
     kphp::log::warning("can't encode data of length {} due to zlib error {}", data.size(), deflate_res);
     return {};
   }
@@ -120,9 +119,8 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
   runtime_ctx.static_SB.clean().reserve(StringInstanceState::STATIC_BUFFER_LENGTH);
   zstrm.avail_out = StringInstanceState::STATIC_BUFFER_LENGTH;
   zstrm.next_out = reinterpret_cast<Bytef*>(runtime_ctx.static_SB.buffer());
-  const auto inflate_res{inflate(std::addressof(zstrm), Z_NO_FLUSH)};
 
-  if (inflate_res != Z_STREAM_END) [[unlikely]] {
+  if (const auto inflate_res{inflate(std::addressof(zstrm), Z_NO_FLUSH)}; inflate_res != Z_STREAM_END) [[unlikely]] {
     kphp::log::warning("can't decode data of length {} due to zlib error {}", data.size(), inflate_res);
     return {};
   }
@@ -138,8 +136,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   int32_t window{15};
   auto strategy{Z_DEFAULT_STRATEGY};
   constexpr auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
-    const mixed& value{option.get_value()};
-    if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
+    if (const mixed & value{option.get_value()}; value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
       dst = value.as_int();
       return true;
     } else {
@@ -187,8 +184,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
           strategy = value.as_int();
           break;
         default:
-          kphp::log::warning(
-              "option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+          kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
           return {};
         }
       } else {
@@ -218,8 +214,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     encoding -= 15 - window;
   }
 
-  auto err{deflateInit2(stream, level, Z_DEFLATED, encoding, memory, strategy)};
-  if (err != Z_OK) {
+  if (auto err{deflateInit2(stream, level, Z_DEFLATED, encoding, memory, strategy)}; err != Z_OK) {
     kphp::log::warning("zlib error {}", zError(err));
     context.destroy();
     return {};
@@ -237,8 +232,7 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
   case Z_FINISH:
     break;
   default:
-    kphp::log::warning(
-        "flush type should be one of ZLIB_NO_FLUSH, ZLIB_PARTIAL_FLUSH, ZLIB_SYNC_FLUSH, ZLIB_FULL_FLUSH, ZLIB_FINISH, ZLIB_BLOCK, ZLIB_TREES");
+    kphp::log::warning("flush type should be one of ZLIB_NO_FLUSH, ZLIB_PARTIAL_FLUSH, ZLIB_SYNC_FLUSH, ZLIB_FULL_FLUSH, ZLIB_FINISH, ZLIB_BLOCK, ZLIB_TREES");
     return {};
   }
 

From 35588e63c3687a26e2218edd899dc79e7779e3cf Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 14:22:26 +0300
Subject: [PATCH 11/39] fix message

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index e8e4aff085..614661ff61 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -140,7 +140,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
       dst = value.as_int();
       return true;
     } else {
-      kphp::log::warning("deflate_init() : option {} should be number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
+      kphp::log::warning("option {} should be number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
       return false;
     }
   }};

From f9e14460198ac2be95877423da8e4d3da4304b52 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 16:37:52 +0300
Subject: [PATCH 12/39] fixes

---
 .../stdlib/zlib/{deflatecontext.h => deflate-context.h}      | 5 +++++
 runtime-light/stdlib/zlib/zlib-functions.h                   | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)
 rename runtime-light/stdlib/zlib/{deflatecontext.h => deflate-context.h} (72%)

diff --git a/runtime-light/stdlib/zlib/deflatecontext.h b/runtime-light/stdlib/zlib/deflate-context.h
similarity index 72%
rename from runtime-light/stdlib/zlib/deflatecontext.h
rename to runtime-light/stdlib/zlib/deflate-context.h
index 5ea4f94a99..bd68d02044 100644
--- a/runtime-light/stdlib/zlib/deflatecontext.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -13,6 +13,11 @@ struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, pri
   C$DeflateContext() noexcept = default;
   using DummyVisitorMethods::accept;
 
+  C$DeflateContext(const C$DeflateContext&) = delete;
+  C$DeflateContext(C$DeflateContext&&) = delete;
+  C$DeflateContext& operator=(const C$DeflateContext&) = delete;
+  C$DeflateContext& operator=(C$DeflateContext&&) = delete;
+
   ~C$DeflateContext() {
     deflateEnd(std::addressof(stream));
   }
diff --git a/runtime-light/stdlib/zlib/zlib-functions.h b/runtime-light/stdlib/zlib/zlib-functions.h
index d23dc1345f..3168e3d4af 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.h
+++ b/runtime-light/stdlib/zlib/zlib-functions.h
@@ -10,7 +10,7 @@
 #include <span>
 
 #include "runtime-common/core/runtime-core.h"
-#include "runtime-light/stdlib/zlib/deflatecontext.h"
+#include "runtime-light/stdlib/zlib/deflate-context.h"
 
 namespace kphp::zlib {
 

From 493d2616df414314f8f81ceb8ad559aff80d03d0 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 16:38:11 +0300
Subject: [PATCH 13/39] 2025

---
 runtime-light/stdlib/zlib/deflate-context.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/deflate-context.h b/runtime-light/stdlib/zlib/deflate-context.h
index bd68d02044..4b030981d2 100644
--- a/runtime-light/stdlib/zlib/deflate-context.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -1,5 +1,5 @@
 // Compiler for PHP (aka KPHP)
-// Copyright (c) 2024 LLC «V Kontakte»
+// Copyright (c) 2025 LLC «V Kontakte»
 // Distributed under the GPL v3 License, see LICENSE.notice.txt
 
 #pragma once

From 252a1e87b11d931ab0d9e45fba3a5fb594324785 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 16:41:32 +0300
Subject: [PATCH 14/39] do not check `zlib_dynamic_free` arg

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 614661ff61..e2d53743f7 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -46,9 +46,6 @@ voidpf zlib_dynamic_alloc([[maybe_unused]] voidpf opaque, uInt items, uInt size)
 }
 
 void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept {
-  if (address == nullptr) [[unlikely]] {
-    return;
-  }
   kphp::memory::script::free(address);
 }
 

From c31bb20369e55901975ae54dc14c6544415aaa28 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 16:50:17 +0300
Subject: [PATCH 15/39] move value declaration

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index e2d53743f7..6f3bd59c1b 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -141,6 +141,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
       return false;
     }
   }};
+
   switch (encoding) {
   case kphp::zlib::ENCODING_RAW:
   case kphp::zlib::ENCODING_DEFLATE:
@@ -150,13 +151,14 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     kphp::log::warning("encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
     return {};
   }
+
   for (const auto& option : options) {
-    mixed value;
     if (!option.is_string_key()) {
       kphp::log::warning("unsupported option");
       return {};
     }
-    const auto& key = option.get_string_key();
+
+    const auto& key{option.get_string_key()};
     if (std::string_view{key.c_str(), key.size()} == "level") {
       if (!extract_int_option(-1, 9, option, level)) {
         return {};
@@ -170,8 +172,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
         return {};
       }
     } else if (std::string_view{key.c_str(), key.size()} == "strategy") {
-      value = option.get_value();
-      if (value.is_int()) {
+      if (mixed value{option.get_value()}; value.is_int()) {
         switch (value.as_int()) {
         case Z_FILTERED:
         case Z_HUFFMAN_ONLY:

From 81c5ae7cc420867049ec0c3113b12b21694d94c1 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Fri, 19 Dec 2025 17:03:36 +0300
Subject: [PATCH 16/39] constants

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 6f3bd59c1b..45ac6d02b4 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -221,6 +221,9 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 }
 
 Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context, const string& data, int64_t flush_type) noexcept {
+  constexpr uint64_t EXTRA_OUT_SIZE{30};
+  constexpr uint64_t MIN_OUT_SIZE{64};
+
   switch (flush_type) {
   case Z_BLOCK:
   case Z_NO_FLUSH:
@@ -235,8 +238,8 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
   }
 
   z_stream* stream{std::addressof(context.get()->stream)};
-  auto out_size{deflateBound(stream, data.size()) + 30};
-  out_size = out_size < 64 ? 64 : out_size;
+  auto out_size{deflateBound(stream, data.size()) + EXTRA_OUT_SIZE};
+  out_size = out_size < MIN_OUT_SIZE ? MIN_OUT_SIZE : out_size;
   string out{static_cast<string::size_type>(out_size), false};
   stream->next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(data.c_str()));
   stream->next_out = reinterpret_cast<Bytef*>(out.buffer());
@@ -247,9 +250,9 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
   uint64_t buffer_used{};
   do {
     if (stream->avail_out == 0) {
-      out.reserve_at_least(out_size + 64);
-      out_size += 64;
-      stream->avail_out = 64;
+      out.reserve_at_least(out_size + MIN_OUT_SIZE);
+      out_size += MIN_OUT_SIZE;
+      stream->avail_out = MIN_OUT_SIZE;
       stream->next_out = reinterpret_cast<Bytef*>(std::next(out.buffer(), buffer_used));
     }
     status = deflate(stream, flush_type);

From db995c81914c80e849b7c891b70982361e48490d Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:08:19 +0300
Subject: [PATCH 17/39] alloc -> calloc

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 45ac6d02b4..cda39ce072 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -37,10 +37,10 @@ voidpf zlib_static_alloc(voidpf opaque, uInt items, uInt size) noexcept {
 
 void zlib_static_free([[maybe_unused]] voidpf opaque, [[maybe_unused]] voidpf address) noexcept {}
 
-voidpf zlib_dynamic_alloc([[maybe_unused]] voidpf opaque, uInt items, uInt size) noexcept {
+voidpf zlib_dynamic_calloc([[maybe_unused]] voidpf opaque, uInt items, uInt size) noexcept {
   auto* mem{kphp::memory::script::calloc(items, size)};
   if (mem == nullptr) [[unlikely]] {
-    kphp::log::warning("zlib dynamic alloc: can't allocate {} bytes", items * size);
+    kphp::log::warning("zlib dynamic calloc: can't allocate {} bytes", items * size);
   }
   return mem;
 }
@@ -202,7 +202,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   context.alloc();
 
   z_stream* stream{std::addressof(context.get()->stream)};
-  stream->zalloc = zlib_dynamic_alloc;
+  stream->zalloc = zlib_dynamic_calloc;
   stream->zfree = zlib_dynamic_free;
   stream->opaque = nullptr;
 

From 487b127bd8e587427d356140ac861cba21556f5e Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:30:16 +0300
Subject: [PATCH 18/39] format

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index cda39ce072..01b8f8c277 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -133,7 +133,8 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   int32_t window{15};
   auto strategy{Z_DEFAULT_STRATEGY};
   constexpr auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
-    if (const mixed & value{option.get_value()}; value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
+    const mixed& value{option.get_value()};
+    if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
       dst = value.as_int();
       return true;
     } else {

From 4083e72ce2b1cd4849345b7dbc0bbe8cc179c4f5 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:35:02 +0300
Subject: [PATCH 19/39] a number

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 01b8f8c277..20cec49e5b 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -138,7 +138,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
       dst = value.as_int();
       return true;
     } else {
-      kphp::log::warning("option {} should be number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
+      kphp::log::warning("option {} should be a number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
       return false;
     }
   }};

From b84e2821a79d84166b1d9fcd7559601d192aba00 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:41:32 +0300
Subject: [PATCH 20/39] default values of options

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 20cec49e5b..0254011f2d 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -128,9 +128,13 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 } // namespace kphp::zlib
 
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
-  int32_t level{-1};
-  int32_t memory{8};
-  int32_t window{15};
+  constexpr int32_t default_level{-1};
+  constexpr int32_t default_memory{8};
+  constexpr int32_t default_window{15};
+
+  int32_t level{default_level};
+  int32_t memory{default_memory};
+  int32_t window{default_window};
   auto strategy{Z_DEFAULT_STRATEGY};
   constexpr auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
     const mixed& value{option.get_value()};

From 91f5b7fe916953bdcba0aa603ae6cffcd77d8556 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:43:17 +0300
Subject: [PATCH 21/39] #include "zlib/zlib.h"

---
 runtime-light/stdlib/zlib/zlib-functions.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.h b/runtime-light/stdlib/zlib/zlib-functions.h
index 3168e3d4af..02de5c5fb5 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.h
+++ b/runtime-light/stdlib/zlib/zlib-functions.h
@@ -9,6 +9,8 @@
 #include <optional>
 #include <span>
 
+#include "zlib/zlib.h"
+
 #include "runtime-common/core/runtime-core.h"
 #include "runtime-light/stdlib/zlib/deflate-context.h"
 

From 64bb8a96ffb9bd8cf10eb68738d3b0447e4b58e3 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 14:44:08 +0300
Subject: [PATCH 22/39] swap two lines

---
 runtime-light/stdlib/zlib/deflate-context.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/deflate-context.h b/runtime-light/stdlib/zlib/deflate-context.h
index 4b030981d2..f43d622479 100644
--- a/runtime-light/stdlib/zlib/deflate-context.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -10,8 +10,8 @@
 #include "runtime-common/stdlib/visitors/dummy-visitor-methods.h"
 
 struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, private DummyVisitorMethods {
-  C$DeflateContext() noexcept = default;
   using DummyVisitorMethods::accept;
+  C$DeflateContext() noexcept = default;
 
   C$DeflateContext(const C$DeflateContext&) = delete;
   C$DeflateContext(C$DeflateContext&&) = delete;

From 283b98ff5be1d219b66f3105e16571384d96ef77 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 15:50:49 +0300
Subject: [PATCH 23/39] small refactoring

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 66 ++++++++++----------
 1 file changed, 33 insertions(+), 33 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 0254011f2d..b5a166c27f 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -128,25 +128,12 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 } // namespace kphp::zlib
 
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
+  using namespace std::literals;
+
   constexpr int32_t default_level{-1};
   constexpr int32_t default_memory{8};
   constexpr int32_t default_window{15};
 
-  int32_t level{default_level};
-  int32_t memory{default_memory};
-  int32_t window{default_window};
-  auto strategy{Z_DEFAULT_STRATEGY};
-  constexpr auto extract_int_option{[](int32_t lbound, int32_t ubound, const array_iterator<const mixed>& option, int32_t& dst) noexcept {
-    const mixed& value{option.get_value()};
-    if (value.is_int() && value.as_int() >= lbound && value.as_int() <= ubound) {
-      dst = value.as_int();
-      return true;
-    } else {
-      kphp::log::warning("option {} should be a number between {}..{}", option.get_string_key().c_str(), lbound, ubound);
-      return false;
-    }
-  }};
-
   switch (encoding) {
   case kphp::zlib::ENCODING_RAW:
   case kphp::zlib::ENCODING_DEFLATE:
@@ -157,6 +144,21 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     return {};
   }
 
+  int32_t level{default_level};
+  int32_t memory{default_memory};
+  int32_t window{default_window};
+  auto strategy{Z_DEFAULT_STRATEGY};
+
+  constexpr auto extract_int{[](int32_t min, int32_t max, const auto& opt, int32_t& dst) noexcept {
+    const mixed& val{opt.get_value()};
+    if (val.is_int() && val.as_int() >= min && val.as_int() <= max) {
+      dst = val.as_int();
+      return true;
+    }
+    kphp::log::warning("option {} should be a number between {}..{}", opt.get_string_key().c_str(), min, max);
+    return false;
+  }};
+
   for (const auto& option : options) {
     if (!option.is_string_key()) {
       kphp::log::warning("unsupported option");
@@ -164,27 +166,29 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     }
 
     const auto& key{option.get_string_key()};
-    if (std::string_view{key.c_str(), key.size()} == "level") {
-      if (!extract_int_option(-1, 9, option, level)) {
+    if (const std::string_view key_view{key.c_str(), key.size()}; key_view == "level"sv) {
+      if (!extract_int(-1, 9, option, level)) {
         return {};
       }
-    } else if (std::string_view{key.c_str(), key.size()} == "memory") {
-      if (!extract_int_option(1, 9, option, memory)) {
+    } else if (key_view == "memory"sv) {
+      if (!extract_int(1, 9, option, memory)) {
         return {};
       }
-    } else if (std::string_view{key.c_str(), key.size()} == "window") {
-      if (!extract_int_option(8, 15, option, window)) {
+    } else if (key_view == "window"sv) {
+      if (!extract_int(8, 15, option, window)) {
         return {};
       }
-    } else if (std::string_view{key.c_str(), key.size()} == "strategy") {
-      if (mixed value{option.get_value()}; value.is_int()) {
-        switch (value.as_int()) {
+    } else if (key_view == "strategy"sv) {
+      const mixed& val{option.get_value()};
+      if (val.is_int()) {
+        const auto s{val.as_int()};
+        switch (s) {
         case Z_FILTERED:
         case Z_HUFFMAN_ONLY:
         case Z_RLE:
         case Z_FIXED:
         case Z_DEFAULT_STRATEGY:
-          strategy = value.as_int();
+          strategy = s;
           break;
         default:
           kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
@@ -194,11 +198,11 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
         kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
         return {};
       }
-    } else if (std::string_view{key.c_str(), key.size()} == "dictionary") {
+    } else if (key_view == "dictionary"sv) {
       kphp::log::warning("option dictionary isn't supported yet");
       return {};
     } else {
-      kphp::log::warning("unknown option name \"{}\"", option.get_string_key().c_str());
+      kphp::log::warning("unknown option name \"{}\"", key.c_str());
       return {};
     }
   }
@@ -211,13 +215,9 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   stream->zfree = zlib_dynamic_free;
   stream->opaque = nullptr;
 
-  if (encoding < 0) {
-    encoding += 15 - window;
-  } else {
-    encoding -= 15 - window;
-  }
+  const auto window_bits{encoding < 0 ? encoding + (15 - window) : encoding - (15 - window)};
 
-  if (auto err{deflateInit2(stream, level, Z_DEFLATED, encoding, memory, strategy)}; err != Z_OK) {
+  if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
     kphp::log::warning("zlib error {}", zError(err));
     context.destroy();
     return {};

From cf25e79316dcf0528a6c5786bab1ac4ce3911f6b Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 15:53:20 +0300
Subject: [PATCH 24/39] using make_instance

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index b5a166c27f..5cd530cb36 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -207,8 +207,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     }
   }
 
-  class_instance<C$DeflateContext> context;
-  context.alloc();
+  auto context{make_instance<C$DeflateContext>()};
 
   z_stream* stream{std::addressof(context.get()->stream)};
   stream->zalloc = zlib_dynamic_calloc;

From d4e8751cfc83114345e2cd78c912eb254ac9403f Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 18:01:30 +0300
Subject: [PATCH 25/39] yet another refactoring

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 89 ++++++++++++--------
 1 file changed, 53 insertions(+), 36 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 5cd530cb36..a445e73c24 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -22,6 +22,8 @@
 
 namespace {
 
+enum class zlib_format : int8_t { raw, deflate, gzip };
+
 voidpf zlib_static_alloc(voidpf opaque, uInt items, uInt size) noexcept {
   auto* buf_pos_ptr{reinterpret_cast<size_t*>(opaque)};
   auto required_mem{static_cast<size_t>(items * size)};
@@ -49,6 +51,31 @@ void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept
   kphp::memory::script::free(address);
 }
 
+std::optional<zlib_format> parse_encoding(int64_t encoding) noexcept {
+  if (encoding == kphp::zlib::ENCODING_GZIP) {
+    return zlib_format::gzip;
+  }
+  if (encoding == kphp::zlib::ENCODING_RAW) {
+    return zlib_format::raw;
+  }
+  if (encoding == kphp::zlib::ENCODING_DEFLATE) {
+    return zlib_format::deflate;
+  }
+  return std::nullopt;
+}
+
+int32_t to_zlib_window_bits(zlib_format format, int32_t window) noexcept {
+  switch (format) {
+  case zlib_format::gzip:
+    return 16 + window;
+  case zlib_format::raw:
+    return -window;
+  case zlib_format::deflate:
+    return window;
+  }
+  return window;
+}
+
 } // namespace
 
 namespace kphp::zlib {
@@ -130,67 +157,57 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
   using namespace std::literals;
 
-  constexpr int32_t default_level{-1};
   constexpr int32_t default_memory{8};
   constexpr int32_t default_window{15};
 
-  switch (encoding) {
-  case kphp::zlib::ENCODING_RAW:
-  case kphp::zlib::ENCODING_DEFLATE:
-  case kphp::zlib::ENCODING_GZIP:
-    break;
-  default:
+  const auto opt_format{parse_encoding(encoding)};
+  if (!opt_format.has_value()) [[unlikely]] {
     kphp::log::warning("encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
     return {};
   }
 
-  int32_t level{default_level};
+  int32_t level{Z_DEFAULT_COMPRESSION};
   int32_t memory{default_memory};
   int32_t window{default_window};
-  auto strategy{Z_DEFAULT_STRATEGY};
-
-  constexpr auto extract_int{[](int32_t min, int32_t max, const auto& opt, int32_t& dst) noexcept {
-    const mixed& val{opt.get_value()};
-    if (val.is_int() && val.as_int() >= min && val.as_int() <= max) {
-      dst = val.as_int();
-      return true;
-    }
-    kphp::log::warning("option {} should be a number between {}..{}", opt.get_string_key().c_str(), min, max);
-    return false;
-  }};
+  int32_t strategy{Z_DEFAULT_STRATEGY};
 
-  for (const auto& option : options) {
-    if (!option.is_string_key()) {
+  for (const auto& it : options) {
+    if (!it.is_string_key()) {
       kphp::log::warning("unsupported option");
       return {};
     }
 
-    const auto& key{option.get_string_key()};
-    if (const std::string_view key_view{key.c_str(), key.size()}; key_view == "level"sv) {
-      if (!extract_int(-1, 9, option, level)) {
+    const auto& key{it.get_string_key()};
+    const std::string_view key_view{key.c_str(), key.size()};
+    const mixed& val{it.get_value()};
+
+    if (key_view == "level"sv) {
+      if (val.is_int() && val.as_int() >= -1 && val.as_int() <= 9) {
+        level = val.as_int();
+      } else {
+        kphp::log::warning("option level should be a number between -1..9");
         return {};
       }
     } else if (key_view == "memory"sv) {
-      if (!extract_int(1, 9, option, memory)) {
+      if (val.is_int() && val.as_int() >= 1 && val.as_int() <= 9) {
+        memory = val.as_int();
+      } else {
+        kphp::log::warning("option memory should be a number between 1..9");
         return {};
       }
     } else if (key_view == "window"sv) {
-      if (!extract_int(8, 15, option, window)) {
+      if (val.is_int() && val.as_int() >= 8 && val.as_int() <= 15) {
+        window = val.as_int();
+      } else {
+        kphp::log::warning("option window should be a number between 8..15");
         return {};
       }
     } else if (key_view == "strategy"sv) {
-      const mixed& val{option.get_value()};
       if (val.is_int()) {
         const auto s{val.as_int()};
-        switch (s) {
-        case Z_FILTERED:
-        case Z_HUFFMAN_ONLY:
-        case Z_RLE:
-        case Z_FIXED:
-        case Z_DEFAULT_STRATEGY:
+        if (s == Z_DEFAULT_STRATEGY || s == Z_FILTERED || s == Z_HUFFMAN_ONLY || s == Z_RLE || s == Z_FIXED) {
           strategy = s;
-          break;
-        default:
+        } else {
           kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
           return {};
         }
@@ -214,7 +231,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   stream->zfree = zlib_dynamic_free;
   stream->opaque = nullptr;
 
-  const auto window_bits{encoding < 0 ? encoding + (15 - window) : encoding - (15 - window)};
+  const int32_t window_bits{to_zlib_window_bits(*opt_format, window)};
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
     kphp::log::warning("zlib error {}", zError(err));

From 5f3208b96a4c6bf5bc26f7df8914e2e45a9b82d0 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 18:03:49 +0300
Subject: [PATCH 26/39] do not use `zError`

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index a445e73c24..b67fc576a5 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -234,7 +234,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   const int32_t window_bits{to_zlib_window_bits(*opt_format, window)};
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
-    kphp::log::warning("zlib error {}", zError(err));
+    kphp::log::warning("zlib error {}", err);
     context.destroy();
     return {};
   }
@@ -292,7 +292,7 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     out.shrink(len);
     return out;
   default:
-    kphp::log::warning("zlib error {}", zError(status));
+    kphp::log::warning("zlib error {}", status);
     return {};
   }
 }

From bd66d0f5729ce5bea38d38e9368cc7c7050e04c9 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 18:11:36 +0300
Subject: [PATCH 27/39] hide `destroy` invocation

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index b67fc576a5..9984419819 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -235,7 +235,6 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
     kphp::log::warning("zlib error {}", err);
-    context.destroy();
     return {};
   }
   return context;

From 164e15cd7f716a6f183f7cf8a114578b441d5578 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 20:54:45 +0300
Subject: [PATCH 28/39] include <memory>

---
 runtime-light/stdlib/zlib/deflate-context.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/runtime-light/stdlib/zlib/deflate-context.h b/runtime-light/stdlib/zlib/deflate-context.h
index f43d622479..1e1e6815be 100644
--- a/runtime-light/stdlib/zlib/deflate-context.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "zlib/zlib.h"
 
 #include "runtime-common/core/class-instance/refcountable-php-classes.h"

From c1a1f495a946e3eb4164a92fdc5324ae8b321b98 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 21:35:37 +0300
Subject: [PATCH 29/39] remove zlib_format

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 40 ++++++++------------
 1 file changed, 16 insertions(+), 24 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 9984419819..e2d52c00f5 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -22,8 +22,6 @@
 
 namespace {
 
-enum class zlib_format : int8_t { raw, deflate, gzip };
-
 voidpf zlib_static_alloc(voidpf opaque, uInt items, uInt size) noexcept {
   auto* buf_pos_ptr{reinterpret_cast<size_t*>(opaque)};
   auto required_mem{static_cast<size_t>(items * size)};
@@ -51,29 +49,24 @@ void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept
   kphp::memory::script::free(address);
 }
 
-std::optional<zlib_format> parse_encoding(int64_t encoding) noexcept {
-  if (encoding == kphp::zlib::ENCODING_GZIP) {
-    return zlib_format::gzip;
-  }
-  if (encoding == kphp::zlib::ENCODING_RAW) {
-    return zlib_format::raw;
-  }
-  if (encoding == kphp::zlib::ENCODING_DEFLATE) {
-    return zlib_format::deflate;
-  }
-  return std::nullopt;
-}
-
-int32_t to_zlib_window_bits(zlib_format format, int32_t window) noexcept {
-  switch (format) {
-  case zlib_format::gzip:
+/**
+ * Maps KPHP encoding constants and custom window size to zlib windowBits.
+ * zlib windowBits logic:
+ *   8..15  -> ZLIB header
+ *  -8..-15 -> RAW (no header)
+ *   24..31 -> GZIP (16 + window)
+ */
+int32_t to_zlib_window_bits(int64_t encoding, int32_t window) noexcept {
+  switch (encoding) {
+  case kphp::zlib::ENCODING_GZIP:
     return 16 + window;
-  case zlib_format::raw:
+  case kphp::zlib::ENCODING_RAW:
     return -window;
-  case zlib_format::deflate:
+  case kphp::zlib::ENCODING_DEFLATE:
     return window;
+  default:
+    kphp::log::error("to_zlib_window_bits: unknown encoding {}", encoding);
   }
-  return window;
 }
 
 } // namespace
@@ -160,8 +153,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   constexpr int32_t default_memory{8};
   constexpr int32_t default_window{15};
 
-  const auto opt_format{parse_encoding(encoding)};
-  if (!opt_format.has_value()) [[unlikely]] {
+  if (encoding != kphp::zlib::ENCODING_RAW && encoding != kphp::zlib::ENCODING_DEFLATE && encoding != kphp::zlib::ENCODING_GZIP) {
     kphp::log::warning("encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
     return {};
   }
@@ -231,7 +223,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   stream->zfree = zlib_dynamic_free;
   stream->opaque = nullptr;
 
-  const int32_t window_bits{to_zlib_window_bits(*opt_format, window)};
+  const int32_t window_bits{to_zlib_window_bits(encoding, window)};
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
     kphp::log::warning("zlib error {}", err);

From 89c14b9f1fbaa8333f563408ac2804d0b3e1c0fa Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 21:43:37 +0300
Subject: [PATCH 30/39] move "using namespace std::literals" into for loop

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index e2d52c00f5..8202acb1b6 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -148,8 +148,6 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 } // namespace kphp::zlib
 
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
-  using namespace std::literals;
-
   constexpr int32_t default_memory{8};
   constexpr int32_t default_window{15};
 
@@ -164,6 +162,8 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   int32_t strategy{Z_DEFAULT_STRATEGY};
 
   for (const auto& it : options) {
+    using namespace std::literals;
+
     if (!it.is_string_key()) {
       kphp::log::warning("unsupported option");
       return {};

From 27a71d1dd9460f2413ceadbdd4f784bdba945dfe Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Mon, 12 Jan 2026 21:47:02 +0300
Subject: [PATCH 31/39] const auto& val

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 8202acb1b6..980f67c9ba 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -171,7 +171,7 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 
     const auto& key{it.get_string_key()};
     const std::string_view key_view{key.c_str(), key.size()};
-    const mixed& val{it.get_value()};
+    const auto& val{it.get_value()};
 
     if (key_view == "level"sv) {
       if (val.is_int() && val.as_int() >= -1 && val.as_int() <= 9) {

From 6c414ec2bd26058afe3d82f2de4f4daf3a0666b1 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 13 Jan 2026 12:36:27 +0300
Subject: [PATCH 32/39] constants

---
 runtime-light/stdlib/zlib/zlib-functions.cpp |  6 +++---
 runtime-light/stdlib/zlib/zlib-functions.h   | 18 ++++++++++++------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 980f67c9ba..016120d55f 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -174,21 +174,21 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     const auto& val{it.get_value()};
 
     if (key_view == "level"sv) {
-      if (val.is_int() && val.as_int() >= -1 && val.as_int() <= 9) {
+      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_COMPRESSION_LEVEL && val.as_int() <= kphp::zlib::MAX_COMPRESSION_LEVEL) {
         level = val.as_int();
       } else {
         kphp::log::warning("option level should be a number between -1..9");
         return {};
       }
     } else if (key_view == "memory"sv) {
-      if (val.is_int() && val.as_int() >= 1 && val.as_int() <= 9) {
+      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_MEMORY_LEVEL && val.as_int() <= kphp::zlib::MAX_MEMORY_LEVEL) {
         memory = val.as_int();
       } else {
         kphp::log::warning("option memory should be a number between 1..9");
         return {};
       }
     } else if (key_view == "window"sv) {
-      if (val.is_int() && val.as_int() >= 8 && val.as_int() <= 15) {
+      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_WINDOW_SIZE && val.as_int() <= kphp::zlib::MAX_WINDOW_SIZE) {
         window = val.as_int();
       } else {
         kphp::log::warning("option window should be a number between 8..15");
diff --git a/runtime-light/stdlib/zlib/zlib-functions.h b/runtime-light/stdlib/zlib/zlib-functions.h
index 02de5c5fb5..0da9ef7e16 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.h
+++ b/runtime-light/stdlib/zlib/zlib-functions.h
@@ -16,13 +16,19 @@
 
 namespace kphp::zlib {
 
-inline constexpr int64_t ENCODING_RAW = -0x0f;
-inline constexpr int64_t ENCODING_DEFLATE = 0x0f;
-inline constexpr int64_t ENCODING_GZIP = 0x1f;
+inline constexpr int64_t ENCODING_RAW{-0x0f};
+inline constexpr int64_t ENCODING_DEFLATE{0x0f};
+inline constexpr int64_t ENCODING_GZIP{0x1f};
 
-inline constexpr int64_t MIN_COMPRESSION_LEVEL = -1;
-inline constexpr int64_t MAX_COMPRESSION_LEVEL = 9;
-inline constexpr int64_t DEFAULT_COMPRESSION_LEVEL = 6;
+inline constexpr int64_t MIN_COMPRESSION_LEVEL{-1};
+inline constexpr int64_t MAX_COMPRESSION_LEVEL{9};
+inline constexpr int64_t DEFAULT_COMPRESSION_LEVEL{6};
+
+inline constexpr int64_t MIN_MEMORY_LEVEL{1};
+inline constexpr int64_t MAX_MEMORY_LEVEL{9};
+
+inline constexpr int64_t MIN_WINDOW_SIZE{8};
+inline constexpr int64_t MAX_WINDOW_SIZE{15};
 
 std::optional<string> encode(std::span<const char> data, int64_t level, int64_t encoding) noexcept;
 

From 702ec51bee2d103bb0fbf1f2921f2824e134bfc0 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 13 Jan 2026 12:55:30 +0300
Subject: [PATCH 33/39] early return

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 31 ++++++++------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 016120d55f..8f4ae68c96 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -174,39 +174,34 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     const auto& val{it.get_value()};
 
     if (key_view == "level"sv) {
-      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_COMPRESSION_LEVEL && val.as_int() <= kphp::zlib::MAX_COMPRESSION_LEVEL) {
-        level = val.as_int();
-      } else {
+      if (!val.is_int() || val.as_int() < kphp::zlib::MIN_COMPRESSION_LEVEL || val.as_int() > kphp::zlib::MAX_COMPRESSION_LEVEL) {
         kphp::log::warning("option level should be a number between -1..9");
         return {};
       }
+      level = val.as_int();
     } else if (key_view == "memory"sv) {
-      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_MEMORY_LEVEL && val.as_int() <= kphp::zlib::MAX_MEMORY_LEVEL) {
-        memory = val.as_int();
-      } else {
+      if (!val.is_int() || val.as_int() < kphp::zlib::MIN_MEMORY_LEVEL || val.as_int() > kphp::zlib::MAX_MEMORY_LEVEL) {
         kphp::log::warning("option memory should be a number between 1..9");
         return {};
       }
+      memory = val.as_int();
     } else if (key_view == "window"sv) {
-      if (val.is_int() && val.as_int() >= kphp::zlib::MIN_WINDOW_SIZE && val.as_int() <= kphp::zlib::MAX_WINDOW_SIZE) {
-        window = val.as_int();
-      } else {
+      if (!val.is_int() || val.as_int() < kphp::zlib::MIN_WINDOW_SIZE || val.as_int() > kphp::zlib::MAX_WINDOW_SIZE) {
         kphp::log::warning("option window should be a number between 8..15");
         return {};
       }
+      window = val.as_int();
     } else if (key_view == "strategy"sv) {
-      if (val.is_int()) {
-        const auto s{val.as_int()};
-        if (s == Z_DEFAULT_STRATEGY || s == Z_FILTERED || s == Z_HUFFMAN_ONLY || s == Z_RLE || s == Z_FIXED) {
-          strategy = s;
-        } else {
-          kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
-          return {};
-        }
-      } else {
+      if (!val.is_int()) {
         kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
         return {};
       }
+      const auto s{val.as_int()};
+      if (s != Z_DEFAULT_STRATEGY && s != Z_FILTERED && s != Z_HUFFMAN_ONLY && s != Z_RLE && s != Z_FIXED) {
+        kphp::log::warning("option strategy should be one of ZLIB_FILTERED, ZLIB_HUFFMAN_ONLY, ZLIB_RLE, ZLIB_FIXED or ZLIB_DEFAULT_STRATEGY");
+        return {};
+      }
+      strategy = s;
     } else if (key_view == "dictionary"sv) {
       kphp::log::warning("option dictionary isn't supported yet");
       return {};

From bc4ee2d90373bf9fb6d01c67887e6fd6070e84bf Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 13 Jan 2026 12:58:44 +0300
Subject: [PATCH 34/39] static local constants

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 8f4ae68c96..d7276a42bf 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -148,8 +148,8 @@ std::optional<string> decode(std::span<const char> data, int64_t encoding) noexc
 } // namespace kphp::zlib
 
 class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mixed>& options) noexcept {
-  constexpr int32_t default_memory{8};
-  constexpr int32_t default_window{15};
+  static constexpr int32_t DEFAULT_MEMORY{8};
+  static constexpr int32_t DEFAULT_WINDOW{15};
 
   if (encoding != kphp::zlib::ENCODING_RAW && encoding != kphp::zlib::ENCODING_DEFLATE && encoding != kphp::zlib::ENCODING_GZIP) {
     kphp::log::warning("encoding should be one of ZLIB_ENCODING_RAW, ZLIB_ENCODING_DEFLATE, ZLIB_ENCODING_GZIP");
@@ -157,8 +157,8 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
   }
 
   int32_t level{Z_DEFAULT_COMPRESSION};
-  int32_t memory{default_memory};
-  int32_t window{default_window};
+  int32_t memory{DEFAULT_MEMORY};
+  int32_t window{DEFAULT_WINDOW};
   int32_t strategy{Z_DEFAULT_STRATEGY};
 
   for (const auto& it : options) {
@@ -228,8 +228,8 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 }
 
 Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context, const string& data, int64_t flush_type) noexcept {
-  constexpr uint64_t EXTRA_OUT_SIZE{30};
-  constexpr uint64_t MIN_OUT_SIZE{64};
+  static constexpr uint64_t EXTRA_OUT_SIZE{30};
+  static constexpr uint64_t MIN_OUT_SIZE{64};
 
   switch (flush_type) {
   case Z_BLOCK:

From d77b5f3f09e449793aeaed0e2962c15306a3d670 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Tue, 13 Jan 2026 13:03:21 +0300
Subject: [PATCH 35/39] switch-case scopes

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index d7276a42bf..4b0abad72f 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -266,19 +266,21 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     buffer_used = out_size - stream->avail_out;
   } while (status == Z_OK && stream->avail_out == 0);
 
-  std::ptrdiff_t len{};
   switch (status) {
-  case Z_OK:
-    len = std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out);
+  case Z_OK: {
+    auto len{std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out)};
     out.shrink(len);
     return out;
-  case Z_STREAM_END:
-    len = std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out);
+  }
+  case Z_STREAM_END: {
+    auto len{std::distance(reinterpret_cast<Bytef*>(out.buffer()), stream->next_out)};
     deflateReset(stream);
     out.shrink(len);
     return out;
-  default:
+  }
+  default: {
     kphp::log::warning("zlib error {}", status);
     return {};
   }
+  }
 }

From 9bcabd6f8bb38849ad1f3cce087e08af9a5e2d56 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Wed, 14 Jan 2026 12:58:54 +0300
Subject: [PATCH 36/39] do not call `deflateEnd` if `deflateInit2` returned
 error

---
 runtime-light/stdlib/zlib/deflate-context.h  | 7 +++++--
 runtime-light/stdlib/zlib/zlib-functions.cpp | 9 ++++-----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/runtime-light/stdlib/zlib/deflate-context.h b/runtime-light/stdlib/zlib/deflate-context.h
index 1e1e6815be..219ccc287c 100644
--- a/runtime-light/stdlib/zlib/deflate-context.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <optional>
 
 #include "zlib/zlib.h"
 
@@ -21,8 +22,10 @@ struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, pri
   C$DeflateContext& operator=(C$DeflateContext&&) = delete;
 
   ~C$DeflateContext() {
-    deflateEnd(std::addressof(stream));
+    if (stream.has_value()) [[likely]] {
+      deflateEnd(std::addressof(*stream));
+    }
   }
 
-  z_stream stream{};
+  std::optional<z_stream> stream;
 };
diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 4b0abad72f..56bcb0f604 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -213,14 +213,12 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 
   auto context{make_instance<C$DeflateContext>()};
 
-  z_stream* stream{std::addressof(context.get()->stream)};
-  stream->zalloc = zlib_dynamic_calloc;
-  stream->zfree = zlib_dynamic_free;
-  stream->opaque = nullptr;
+  z_stream* stream{std::addressof(context.get()->stream.emplace(z_stream{.zalloc = zlib_dynamic_calloc, .zfree = zlib_dynamic_free, .opaque = nullptr}))};
 
   const int32_t window_bits{to_zlib_window_bits(encoding, window)};
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
+    context.get()->stream = std::nullopt;
     kphp::log::warning("zlib error {}", err);
     return {};
   }
@@ -244,7 +242,8 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     return {};
   }
 
-  z_stream* stream{std::addressof(context.get()->stream)};
+  kphp::log::assertion(context.get()->stream.has_value());
+  z_stream* stream{std::addressof(*context.get()->stream)};
   auto out_size{deflateBound(stream, data.size()) + EXTRA_OUT_SIZE};
   out_size = out_size < MIN_OUT_SIZE ? MIN_OUT_SIZE : out_size;
   string out{static_cast<string::size_type>(out_size), false};

From 5d7f0a179b39ce8194c5c34baeb066b900da0a92 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Wed, 14 Jan 2026 13:05:27 +0300
Subject: [PATCH 37/39] to_zlib_window_bits -> lambda

---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 33 +++++++-------------
 1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index 56bcb0f604..e10fe268b4 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -49,26 +49,6 @@ void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept
   kphp::memory::script::free(address);
 }
 
-/**
- * Maps KPHP encoding constants and custom window size to zlib windowBits.
- * zlib windowBits logic:
- *   8..15  -> ZLIB header
- *  -8..-15 -> RAW (no header)
- *   24..31 -> GZIP (16 + window)
- */
-int32_t to_zlib_window_bits(int64_t encoding, int32_t window) noexcept {
-  switch (encoding) {
-  case kphp::zlib::ENCODING_GZIP:
-    return 16 + window;
-  case kphp::zlib::ENCODING_RAW:
-    return -window;
-  case kphp::zlib::ENCODING_DEFLATE:
-    return window;
-  default:
-    kphp::log::error("to_zlib_window_bits: unknown encoding {}", encoding);
-  }
-}
-
 } // namespace
 
 namespace kphp::zlib {
@@ -215,7 +195,18 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
 
   z_stream* stream{std::addressof(context.get()->stream.emplace(z_stream{.zalloc = zlib_dynamic_calloc, .zfree = zlib_dynamic_free, .opaque = nullptr}))};
 
-  const int32_t window_bits{to_zlib_window_bits(encoding, window)};
+  const int32_t window_bits{[encoding, window] noexcept {
+    switch (encoding) {
+    case kphp::zlib::ENCODING_GZIP:
+      return 16 + window;
+    case kphp::zlib::ENCODING_RAW:
+      return -window;
+    case kphp::zlib::ENCODING_DEFLATE:
+      return window;
+    default:
+      kphp::log::error("deflate_init: unknown encoding {}", encoding);
+    }
+  }()};
 
   if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
     context.get()->stream = std::nullopt;

From 42a3d3412376b25a8cbdfa22066c53903d923a12 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Wed, 14 Jan 2026 14:29:19 +0300
Subject: [PATCH 38/39] move md5_file from zlib-functions.txt into
 file-functions.txt

---
 builtin-functions/kphp-light/stdlib/file-functions.txt | 3 +++
 builtin-functions/kphp-light/stdlib/zlib-functions.txt | 6 ------
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/builtin-functions/kphp-light/stdlib/file-functions.txt b/builtin-functions/kphp-light/stdlib/file-functions.txt
index 334aec33d2..b3ee9e6737 100644
--- a/builtin-functions/kphp-light/stdlib/file-functions.txt
+++ b/builtin-functions/kphp-light/stdlib/file-functions.txt
@@ -102,3 +102,6 @@ function stream_context_create ($options ::: mixed = array()) ::: mixed;
 function fprintf ($stream, $format ::: string, ...$args) ::: int;
 /** @kphp-extern-func-info stub */
 function fputcsv ($stream, $fields ::: array, $delimiter = ",", $enclosure = "\"", $escape = "\\") ::: int | false;
+
+/** @kphp-extern-func-info stub generation-required */
+function md5_file ($s ::: string, $raw_output ::: bool = false) ::: string | false;
diff --git a/builtin-functions/kphp-light/stdlib/zlib-functions.txt b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
index 2121dc2f37..953472780d 100644
--- a/builtin-functions/kphp-light/stdlib/zlib-functions.txt
+++ b/builtin-functions/kphp-light/stdlib/zlib-functions.txt
@@ -39,9 +39,3 @@ function deflate_add(DeflateContext $context, string $data, int $flush_mode = ZL
 final class DeflateContext {
     private function __construct() ::: DeflateContext;
 }
-
-
-// ===== UNSUPPORTED =====
-
-/** @kphp-extern-func-info stub generation-required */
-function md5_file ($s ::: string, $raw_output ::: bool = false) ::: string | false;

From 4f05a770af36b87d51c48f7a8a7dfe6333a9bf38 Mon Sep 17 00:00:00 2001
From: Karim Shamazov <k.shamazov@vkteam.ru>
Date: Wed, 14 Jan 2026 15:28:29 +0300
Subject: [PATCH 39/39] make init method

---
 runtime-light/stdlib/zlib/deflate-context.h  | 42 +++++++++++++++++---
 runtime-light/stdlib/zlib/zlib-functions.cpp | 26 ++----------
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/runtime-light/stdlib/zlib/deflate-context.h b/runtime-light/stdlib/zlib/deflate-context.h
index 219ccc287c..f3ac736a05 100644
--- a/runtime-light/stdlib/zlib/deflate-context.h
+++ b/runtime-light/stdlib/zlib/deflate-context.h
@@ -4,15 +4,33 @@
 
 #pragma once
 
+#include <cstdint>
 #include <memory>
 #include <optional>
 
 #include "zlib/zlib.h"
 
+#include "runtime-common/core/allocator/script-malloc-interface.h"
 #include "runtime-common/core/class-instance/refcountable-php-classes.h"
 #include "runtime-common/stdlib/visitors/dummy-visitor-methods.h"
+#include "runtime-light/stdlib/diagnostics/logs.h"
 
-struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, private DummyVisitorMethods {
+class C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, private DummyVisitorMethods {
+  std::optional<z_stream> m_stream;
+
+  static voidpf dynamic_calloc([[maybe_unused]] voidpf opaque, uInt items, uInt size) noexcept {
+    auto* mem{kphp::memory::script::calloc(items, size)};
+    if (mem == nullptr) [[unlikely]] {
+      kphp::log::warning("zlib dynamic calloc: can't allocate {} bytes", items * size);
+    }
+    return mem;
+  }
+
+  static void dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept {
+    kphp::memory::script::free(address);
+  }
+
+public:
   using DummyVisitorMethods::accept;
   C$DeflateContext() noexcept = default;
 
@@ -21,11 +39,25 @@ struct C$DeflateContext : public refcountable_php_classes<C$DeflateContext>, pri
   C$DeflateContext& operator=(const C$DeflateContext&) = delete;
   C$DeflateContext& operator=(C$DeflateContext&&) = delete;
 
-  ~C$DeflateContext() {
-    if (stream.has_value()) [[likely]] {
-      deflateEnd(std::addressof(*stream));
+  bool init(int32_t level, int32_t window_bits, int32_t memory, int32_t strategy) noexcept {
+    z_stream* stream{std::addressof(m_stream.emplace(z_stream{.zalloc = dynamic_calloc, .zfree = dynamic_free, .opaque = nullptr}))};
+
+    if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
+      kphp::log::warning("zlib error {}", err);
+      return false;
     }
+
+    return true;
+  }
+
+  z_stream& operator*() noexcept {
+    kphp::log::assertion(m_stream.has_value());
+    return *m_stream;
   }
 
-  std::optional<z_stream> stream;
+  ~C$DeflateContext() {
+    if (m_stream.has_value()) [[likely]] {
+      deflateEnd(std::addressof(*m_stream));
+    }
+  }
 };
diff --git a/runtime-light/stdlib/zlib/zlib-functions.cpp b/runtime-light/stdlib/zlib/zlib-functions.cpp
index e10fe268b4..5798b577ed 100644
--- a/runtime-light/stdlib/zlib/zlib-functions.cpp
+++ b/runtime-light/stdlib/zlib/zlib-functions.cpp
@@ -15,7 +15,6 @@
 #include "zlib/zlib.h"
 
 #include "common/containers/final_action.h"
-#include "runtime-common/core/allocator/script-malloc-interface.h"
 #include "runtime-common/core/runtime-core.h"
 #include "runtime-light/stdlib/diagnostics/logs.h"
 #include "runtime-light/stdlib/string/string-state.h"
@@ -37,18 +36,6 @@ voidpf zlib_static_alloc(voidpf opaque, uInt items, uInt size) noexcept {
 
 void zlib_static_free([[maybe_unused]] voidpf opaque, [[maybe_unused]] voidpf address) noexcept {}
 
-voidpf zlib_dynamic_calloc([[maybe_unused]] voidpf opaque, uInt items, uInt size) noexcept {
-  auto* mem{kphp::memory::script::calloc(items, size)};
-  if (mem == nullptr) [[unlikely]] {
-    kphp::log::warning("zlib dynamic calloc: can't allocate {} bytes", items * size);
-  }
-  return mem;
-}
-
-void zlib_dynamic_free([[maybe_unused]] voidpf opaque, voidpf address) noexcept {
-  kphp::memory::script::free(address);
-}
-
 } // namespace
 
 namespace kphp::zlib {
@@ -191,10 +178,6 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     }
   }
 
-  auto context{make_instance<C$DeflateContext>()};
-
-  z_stream* stream{std::addressof(context.get()->stream.emplace(z_stream{.zalloc = zlib_dynamic_calloc, .zfree = zlib_dynamic_free, .opaque = nullptr}))};
-
   const int32_t window_bits{[encoding, window] noexcept {
     switch (encoding) {
     case kphp::zlib::ENCODING_GZIP:
@@ -208,9 +191,9 @@ class_instance<C$DeflateContext> f$deflate_init(int64_t encoding, const array<mi
     }
   }()};
 
-  if (auto err{deflateInit2(stream, level, Z_DEFLATED, window_bits, memory, strategy)}; err != Z_OK) {
-    context.get()->stream = std::nullopt;
-    kphp::log::warning("zlib error {}", err);
+  auto context{make_instance<C$DeflateContext>()};
+
+  if (!context->init(level, window_bits, memory, strategy)) {
     return {};
   }
   return context;
@@ -233,8 +216,7 @@ Optional<string> f$deflate_add(const class_instance<C$DeflateContext>& context,
     return {};
   }
 
-  kphp::log::assertion(context.get()->stream.has_value());
-  z_stream* stream{std::addressof(*context.get()->stream)};
+  z_stream* stream{std::addressof(**context.get())};
   auto out_size{deflateBound(stream, data.size()) + EXTRA_OUT_SIZE};
   out_size = out_size < MIN_OUT_SIZE ? MIN_OUT_SIZE : out_size;
   string out{static_cast<string::size_type>(out_size), false};