Deduplicate identical AndroidBuild members in AndroidBuilds

This reduces re-calculating the same partition information for multiple
builds.

Bug: b/473893997

Author: Databean

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/BUILD.bazel

@@ -22,7 +22,9 @@ cf_cc_library(
     hdrs = ["android_builds.h"],
     deps = [
         "//cuttlefish/host/commands/assemble_cvd/android_build",
+        "//cuttlefish/host/commands/assemble_cvd/android_build:identify_build",
         "//cuttlefish/result",
+        "@abseil-cpp//absl/log:check",
         "@fmt",
     ],
 )
@@ -124,6 +126,7 @@ cf_cc_library(
         "//cuttlefish/result",
         "//libbase",
         "@abseil-cpp//absl/strings",
+        "@fmt",
     ],
 )
 

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/android_builds.cc

@@ -22,45 +22,66 @@
 #include <utility>
 #include <vector>
 
+#include "absl/log/check.h"
+#include "fmt/ostream.h"
+#include "fmt/ranges.h"
+
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
+#include "cuttlefish/host/commands/assemble_cvd/android_build/identify_build.h"
 #include "cuttlefish/result/result.h"
 
 namespace cuttlefish {
 
-Result<AndroidBuilds> AndroidBuilds::Create(
-    std::vector<std::unique_ptr<AndroidBuild>> providers) {
-  CF_EXPECT(!providers.empty());
-  for (const auto& provider : providers) {
-    CF_EXPECT(provider.get());
+Result<AndroidBuilds> AndroidBuilds::Identify(
+    std::vector<AndroidBuildKey> keys) {
+  CF_EXPECT(!keys.empty());
+
+  std::map<AndroidBuildKey, std::unique_ptr<AndroidBuild>> builds_map;
+  for (const AndroidBuildKey& key : keys) {
+    if (builds_map.count(key) > 0) {
+      continue;
+    }
+    std::unique_ptr<AndroidBuild> build = CF_EXPECT(IdentifyAndroidBuild(key));
+    CF_EXPECT(build.get());
+    builds_map[key] = std::move(build);
   }
-  return AndroidBuilds(std::move(providers));
-}
 
-AndroidBuilds::AndroidBuilds(
-    std::vector<std::unique_ptr<AndroidBuild>> providers)
-    : providers_(std::move(providers)) {}
+  CF_EXPECT(!builds_map.empty());
+
+  AndroidBuilds builds;
+  builds.keys_ = std::move(keys);
+  builds.builds_ = std::move(builds_map);
+
+  return builds;
+}
 
-AndroidBuild& AndroidBuilds::ForIndex(size_t index) {
+AndroidBuild& AndroidBuilds::ForIndex(const size_t index) {
   const AndroidBuilds& const_this = *this;
   return const_cast<AndroidBuild&>(const_this.ForIndex(index));
 }
 
 const AndroidBuild& AndroidBuilds::ForIndex(size_t index) const {
-  if (index < providers_.size()) {
-    return *providers_[index];
-  } else {
-    return *providers_[0];
+  if (index >= keys_.size()) {
+    CHECK(!keys_.empty());
+    index = 0;
   }
+  const AndroidBuildKey& key = keys_[index];
+  auto it = builds_.find(key);
+  CHECK(it != builds_.end());
+  CHECK(it->second.get() != nullptr);
+  return *it->second;
 }
 
-size_t AndroidBuilds::Size() const { return providers_.size(); }
+size_t AndroidBuilds::Size() const { return keys_.size(); }
 
-std::ostream& operator<<(std::ostream& out, const AndroidBuilds& providers) {
-  out << "AndroidBuilds {";
-  for (const auto& provider : providers.providers_) {
-    out << *provider << ", ";
+std::ostream& operator<<(std::ostream& out, const AndroidBuilds& builds) {
+  fmt::print(out, "AndroidBuilds {{ .keys_ = [{}], .builds_= {{",
+             fmt::join(builds.keys_, ", "));
+  for (const auto& [key, value] : builds.builds_) {
+    CHECK(value.get() != nullptr);
+    fmt::print(out, "{} -> {}, ", key, *value);
   }
-  return out << "}";
+  return out << "}}";
 };
 
 }  // namespace cuttlefish

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/android_builds.h

@@ -15,18 +15,19 @@
 
 #pragma once
 
+#include <map>
 #include <memory>
 #include <vector>
 
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
+#include "cuttlefish/host/commands/assemble_cvd/android_build/identify_build.h"
 #include "cuttlefish/result/result.h"
 
 namespace cuttlefish {
 
 class AndroidBuilds {
  public:
-  static Result<AndroidBuilds> Create(
-      std::vector<std::unique_ptr<AndroidBuild>>);
+  static Result<AndroidBuilds> Identify(std::vector<AndroidBuildKey>);
 
   AndroidBuild& ForIndex(size_t index);
   const AndroidBuild& ForIndex(size_t index) const;
@@ -36,9 +37,10 @@ class AndroidBuilds {
   friend std::ostream& operator<<(std::ostream&, const AndroidBuilds&);
 
  private:
-  AndroidBuilds(std::vector<std::unique_ptr<AndroidBuild>>);
+  AndroidBuilds() = default;
 
-  std::vector<std::unique_ptr<AndroidBuild>> providers_;
+  std::vector<AndroidBuildKey> keys_;
+  std::map<AndroidBuildKey, std::unique_ptr<AndroidBuild>> builds_;
 };
 
 }  // namespace cuttlefish

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/identify_build.cc

@@ -17,10 +17,11 @@
 
 #include <memory>
 #include <string>
-#include <string_view>
 #include <utility>
 #include <vector>
 
+#include "fmt/ostream.h"
+
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_dist_build.h"
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_product_dir.h"
@@ -34,6 +35,32 @@
 
 namespace cuttlefish {
 
+AndroidBuildKey::AndroidBuildKey(std::string system_image_dir,
+                                 const FetcherConfig& fetcher_config,
+                                 FileSource source)
+    : system_image_dir(std::move(system_image_dir)),
+      fetcher_config(&fetcher_config),
+      source(source) {}
+
+bool operator<(const AndroidBuildKey& left, const AndroidBuildKey& right) {
+  if (left.system_image_dir != right.system_image_dir) {
+    return left.system_image_dir < right.system_image_dir;
+  }
+  if (left.fetcher_config != right.fetcher_config) {
+    return left.fetcher_config < right.fetcher_config;
+  }
+  return left.source < right.source;
+}
+
+std::ostream& operator<<(std::ostream& out, const AndroidBuildKey& key) {
+  fmt::print(out,
+             "AndroidBuildKey {{ .system_image_dir = {}, .fetcher_config = {}, "
+             ".source = {} }}",
+             key.system_image_dir, key.fetcher_config ? "(present)" : "(null)",
+             key.source);
+  return out;
+}
+
 Result<std::unique_ptr<AndroidBuild>> IdentifyAndroidBuild(
     const std::string& system_image_dir, const FetcherConfig& config,
     FileSource source) {
@@ -67,4 +94,12 @@ Result<std::unique_ptr<AndroidBuild>> IdentifyAndroidBuild(
   return build;
 }
 
+Result<std::unique_ptr<AndroidBuild>> IdentifyAndroidBuild(
+    const AndroidBuildKey& android_build_key) {
+  CF_EXPECT_NE(android_build_key.fetcher_config, nullptr);
+  return CF_EXPECT(IdentifyAndroidBuild(android_build_key.system_image_dir,
+                                        *android_build_key.fetcher_config,
+                                        android_build_key.source));
+}
+
 }  // namespace cuttlefish

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/identify_build.h

@@ -18,15 +18,39 @@
 #include <memory>
 #include <string>
 
+#include "fmt/ostream.h"
+
 #include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
 #include "cuttlefish/host/libs/config/fetcher_config.h"
 #include "cuttlefish/host/libs/config/file_source.h"
 #include "cuttlefish/result/result.h"
 
 namespace cuttlefish {
 
+struct AndroidBuildKey {
+  explicit AndroidBuildKey(std::string, const FetcherConfig&, FileSource);
+
+  std::string system_image_dir;
+  const FetcherConfig* fetcher_config;
+  FileSource source;
+};
+
+bool operator<(const AndroidBuildKey&, const AndroidBuildKey&);
+
+std::ostream& operator<<(std::ostream&, const AndroidBuildKey&);
+
 Result<std::unique_ptr<AndroidBuild>> IdentifyAndroidBuild(
     const std::string& system_image_dir, const FetcherConfig& config,
     FileSource source);
 
+Result<std::unique_ptr<AndroidBuild>> IdentifyAndroidBuild(
+    const AndroidBuildKey&);
+
 }  // namespace cuttlefish
+
+namespace fmt {
+
+template <>
+struct formatter<::cuttlefish::AndroidBuildKey> : ostream_formatter {};
+
+}  // namespace fmt

base/cvd/cuttlefish/host/commands/assemble_cvd/assemble_cvd.cc

@@ -538,13 +538,14 @@ Result<AndroidBuilds> FindAndroidBuilds(
   CF_EXPECT_EQ(system_image_dir.Size(), fetcher_configs.Size());
   std::vector<std::unique_ptr<AndroidBuild>> android_builds;
 
+  std::vector<AndroidBuildKey> keys;
   for (size_t i = 0; i < system_image_dir.Size(); i++) {
-    android_builds.emplace_back(CF_EXPECT(IdentifyAndroidBuild(
-        system_image_dir.ForIndex(i), fetcher_configs.ForInstance(i),
-        FileSource::DEFAULT_BUILD)));
+    keys.emplace_back(system_image_dir.ForIndex(i),
+                      fetcher_configs.ForInstance(i),
+                      FileSource::DEFAULT_BUILD);
   }
 
-  return CF_EXPECT(AndroidBuilds::Create(std::move(android_builds)));
+  return CF_EXPECT(AndroidBuilds::Identify(std::move(keys)));
 }
 
 } // namespace