chore: get rid of quicklist encoding (#5282)

c-based quicklist code was being sunset since 01/25.
This PR removes all the references to the quicklist encoding,
greatly simplifying list related logic.

Signed-off-by: Roman Gershman <[email protected]>

Author: romange

.github/workflows/ci.yml

@@ -146,7 +146,7 @@ jobs:
           echo Run ctest -V -L DFLY
 
           GLOG_alsologtostderr=1 GLOG_vmodule=rdb_load=1,rdb_save=1,snapshot=1,op_manager=1,op_manager_test=1 \
-          FLAGS_fiber_safety_margin=4096 FLAGS_list_experimental_v2=true timeout 20m ctest -V -L DFLY -E allocation_tracker_test
+          FLAGS_fiber_safety_margin=4096 timeout 20m ctest -V -L DFLY -E allocation_tracker_test
 
           # Run allocation tracker test separately without alsologtostderr because it generates a TON of logs.
           FLAGS_fiber_safety_margin=4096 timeout 5m ./allocation_tracker_test

src/core/compact_object.cc

@@ -10,7 +10,6 @@
 extern "C" {
 #include "redis/intset.h"
 #include "redis/listpack.h"
-#include "redis/quicklist.h"
 #include "redis/redis_aux.h"
 #include "redis/stream.h"
 #include "redis/util.h"
@@ -43,18 +42,6 @@ namespace {
 constexpr XXH64_hash_t kHashSeed = 24061983;
 constexpr size_t kAlignSize = 8u;
 
-// Approximation since does not account for listpacks.
-size_t QlMAllocSize(quicklist* ql, bool slow) {
-  size_t node_size = ql->len * sizeof(quicklistNode) + znallocx(sizeof(quicklist));
-  if (slow) {
-    for (quicklistNode* node = ql->head; node; node = node->next) {
-      node_size += zmalloc_usable_size(node->entry);
-    }
-    return node_size;
-  }
-  return node_size + ql->count * 16;  // we account for each member 16 bytes.
-}
-
 size_t UpdateSize(size_t size, int64_t update) {
   int64_t result = static_cast<int64_t>(size) + update;
   if (result < 0) {
@@ -80,16 +67,8 @@ inline void FreeObjSet(unsigned encoding, void* ptr, MemoryResource* mr) {
 }
 
 void FreeList(unsigned encoding, void* ptr, MemoryResource* mr) {
-  switch (encoding) {
-    case OBJ_ENCODING_QUICKLIST:
-      quicklistRelease((quicklist*)ptr);
-      break;
-    case kEncodingQL2:
-      CompactObj::DeleteMR<QList>(ptr);
-      break;
-    default:
-      LOG(FATAL) << "Unknown list encoding type";
-  }
+  CHECK_EQ(encoding, kEncodingQL2);
+  CompactObj::DeleteMR<QList>(ptr);
 }
 
 size_t MallocUsedSet(unsigned encoding, void* ptr) {
@@ -409,8 +388,6 @@ size_t RobjWrapper::MallocUsed(bool slow) const {
       CHECK_EQ(OBJ_ENCODING_RAW, encoding_);
       return InnerObjMallocUsed();
     case OBJ_LIST:
-      if (encoding_ == OBJ_ENCODING_QUICKLIST)
-        return QlMAllocSize((quicklist*)inner_obj_, slow);
       return ((QList*)inner_obj_)->MallocUsed(slow);
     case OBJ_SET:
       return MallocUsedSet(encoding_, inner_obj_);
@@ -434,8 +411,6 @@ size_t RobjWrapper::Size() const {
       DCHECK_EQ(OBJ_ENCODING_RAW, encoding_);
       return sz_;
     case OBJ_LIST:
-      if (encoding_ == OBJ_ENCODING_QUICKLIST)
-        return quicklistCount((quicklist*)inner_obj_);
       return ((QList*)inner_obj_)->Size();
     case OBJ_ZSET: {
       switch (encoding_) {

src/core/qlist.h

@@ -30,7 +30,6 @@ class QList {
    * attempted_compress: 1 bit, boolean, used for verifying during testing.
    * dont_compress: 1 bit, boolean, used for preventing compression of entry.
    * extra: 9 bits, free for future use; pads out the remainder of 32 bits
-   * NOTE: do not change the ABI of this struct as long as we support --list_experimental_v2=false
    * */
 
   typedef struct Node {

src/redis/redis_aux.c

@@ -5,7 +5,6 @@
 
 #include "crc64.h"
 #include "endianconv.h"
-#include "quicklist.h"
 #include "zmalloc.h"
 
 Server server;
@@ -49,55 +48,3 @@ uint64_t intrev64(uint64_t v) {
   memrev64(&v);
   return v;
 }
-
-// Based on quicklistGetIteratorAtIdx but without allocations
-void quicklistInitIterator(quicklistIter* iter, quicklist *quicklist, int direction,
-                           const long long idx) {
-    quicklistNode *n = NULL;
-    unsigned long long accum = 0;
-    int forward = idx < 0 ? 0 : 1; /* < 0 -> reverse, 0+ -> forward */
-    unsigned long long index = forward ? idx : (-idx) - 1;
-
-    iter->direction = direction;
-    iter->quicklist = quicklist;
-    iter->current = NULL;
-    iter->zi = NULL;
-
-    if (index >= quicklist->count) return;
-
-    /* Seek in the other direction if that way is shorter. */
-    int seek_forward = forward;
-    unsigned long long seek_index = index;
-    if (index > (quicklist->count - 1) / 2) {
-        seek_forward = !forward;
-        seek_index = quicklist->count - 1 - index;
-    }
-
-    n = seek_forward ? quicklist->head : quicklist->tail;
-    while (likely(n)) {
-        if ((accum + n->count) > seek_index) {
-            break;
-        } else {
-            accum += n->count;
-            n = seek_forward ? n->next : n->prev;
-        }
-    }
-
-    if (!n)
-      return;
-
-    iter->current = n;
-
-    /* Fix accum so it looks like we seeked in the other direction. */
-    if (seek_forward != forward)
-      accum = quicklist->count - n->count - accum;
-
-    if (forward) {
-        /* forward = normal head-to-tail offset. */
-        iter->offset = index - accum;
-    } else {
-        /* reverse = need negative offset for tail-to-head, so undo
-         * the result of the original index = (-idx) - 1 above. */
-        iter->offset = (-index) - 1 + accum;
-    }
-}

src/redis/redis_aux.h

@@ -49,15 +49,10 @@ void InitRedisTables();
 #define OBJ_ENCODING_INTSET 6U  /* Encoded as intset */
 #define OBJ_ENCODING_SKIPLIST 7U  /* Encoded as skiplist */
 #define OBJ_ENCODING_EMBSTR 8U  /* Embedded sds string encoding */
-#define OBJ_ENCODING_QUICKLIST 9U /* Encoded as linked list of ziplists */
+// #define OBJ_ENCODING_QUICKLIST 9U /* Encoded as linked list of ziplists */
 #define OBJ_ENCODING_STREAM 10U /* Encoded as a radix tree of listpacks */
 #define OBJ_ENCODING_LISTPACK 11 /* Encoded as a listpack */
 #define OBJ_ENCODING_COMPRESS_INTERNAL 15U  /* Kept as lzf compressed, to pass compressed blob to another thread */
 
-typedef struct quicklistIter quicklistIter;
-typedef struct quicklist quicklist;
-
-void quicklistInitIterator(quicklistIter* iter, quicklist *quicklist, int direction, const long long idx);
-void quicklistCompressIterator(quicklistIter* iter);
 
 #endif /* __REDIS_AUX_H */

src/server/container_utils.cc

@@ -139,40 +139,9 @@ OpResult<ShardFFResult> FindFirstNonEmpty(Transaction* trans, int req_obj_type)
 
 using namespace std;
 
-quicklistEntry QLEntry() {
-  quicklistEntry res{.quicklist = NULL,
-                     .node = NULL,
-                     .zi = NULL,
-                     .value = NULL,
-                     .longval = 0,
-                     .sz = 0,
-                     .offset = 0};
-  return res;
-}
-
 bool IterateList(const PrimeValue& pv, const IterateFunc& func, long start, long end) {
   bool success = true;
 
-  if (pv.Encoding() == OBJ_ENCODING_QUICKLIST) {
-    quicklist* ql = static_cast<quicklist*>(pv.RObjPtr());
-    long llen = quicklistCount(ql);
-    if (end < 0 || end >= llen)
-      end = llen - 1;
-
-    quicklistIter* qiter = quicklistGetIteratorAtIdx(ql, AL_START_HEAD, start);
-    quicklistEntry entry = QLEntry();
-    long lrange = end - start + 1;
-
-    while (success && quicklistNext(qiter, &entry) && lrange-- > 0) {
-      if (entry.value) {
-        success = func(ContainerEntry{reinterpret_cast<char*>(entry.value), entry.sz});
-      } else {
-        success = func(ContainerEntry{entry.longval});
-      }
-    }
-    quicklistReleaseIterator(qiter);
-    return success;
-  }
   DCHECK_EQ(pv.Encoding(), kEncodingQL2);
   QList* ql = static_cast<QList*>(pv.RObjPtr());
 

src/server/container_utils.h

@@ -9,7 +9,6 @@
 
 extern "C" {
 #include "redis/listpack.h"
-#include "redis/quicklist.h"
 }
 
 #include <functional>
@@ -26,9 +25,6 @@ inline bool IsContainer(const PrimeValue& pv) {
   return (type == OBJ_LIST || type == OBJ_SET || type == OBJ_ZSET);
 }
 
-// Create empty quicklistEntry
-quicklistEntry QLEntry();
-
 // Stores either:
 // - A single long long value (longval) when value = nullptr
 // - A single char* (value) when value != nullptr

src/server/debugcmd.cc

@@ -451,11 +451,7 @@ const char* EncodingName(unsigned obj_type, unsigned encoding) {
     case OBJ_STRING:
       return "raw";
     case OBJ_LIST:
-      switch (encoding) {
-        case kEncodingQL2:
-        case OBJ_ENCODING_QUICKLIST:
-          return "quicklist";
-      }
+      return "quicklist";
       break;
     case OBJ_SET:
       ABSL_FALLTHROUGH_INTENDED;