feat(rdb save): add blob compression on snapshot

docs/build-from-source.md

@@ -17,7 +17,7 @@ git clone --recursive https://github.com/dragonflydb/dragonfly && cd dragonfly
 ```bash
 # Install dependencies
 sudo apt install ninja-build libunwind-dev libboost-fiber-dev libssl-dev \
-     autoconf-archive libtool cmake g++
+     autoconf-archive libtool cmake g++ libzstd-dev
 ```
 
 ## Step 3

src/redis/redis_aux.c

@@ -29,11 +29,9 @@ void InitRedisTables() {
   server.hash_max_listpack_entries = 512;
   server.hash_max_listpack_value = 32;  // decreased from redis default 64.
 
-  server.rdb_compression = 1;
-
   server.stream_node_max_bytes = 4096;
   server.stream_node_max_entries = 100;
- }
+}
 
 // These functions are moved here from server.c
 int htNeedsResize(dict* dict) {
@@ -73,7 +71,7 @@ int dictPtrKeyCompare(dict* privdata, const void* key1, const void* key2) {
   return key1 == key2;
 }
 
-int dictSdsKeyCompare(dict *d, const void* key1, const void* key2) {
+int dictSdsKeyCompare(dict* d, const void* key1, const void* key2) {
   int l1, l2;
   DICT_NOTUSED(d);
 
@@ -84,7 +82,7 @@ int dictSdsKeyCompare(dict *d, const void* key1, const void* key2) {
   return memcmp(key1, key2, l1) == 0;
 }
 
-void dictSdsDestructor(dict *d, void* val) {
+void dictSdsDestructor(dict* d, void* val) {
   DICT_NOTUSED(d);
 
   sdsfree(val);
@@ -100,29 +98,28 @@ size_t sdsZmallocSize(sds s) {
 
 /* Toggle the 64 bit unsigned integer pointed by *p from little endian to
  * big endian */
-void memrev64(void *p) {
-    unsigned char *x = p, t;
-
-    t = x[0];
-    x[0] = x[7];
-    x[7] = t;
-    t = x[1];
-    x[1] = x[6];
-    x[6] = t;
-    t = x[2];
-    x[2] = x[5];
-    x[5] = t;
-    t = x[3];
-    x[3] = x[4];
-    x[4] = t;
+void memrev64(void* p) {
+  unsigned char *x = p, t;
+
+  t = x[0];
+  x[0] = x[7];
+  x[7] = t;
+  t = x[1];
+  x[1] = x[6];
+  x[6] = t;
+  t = x[2];
+  x[2] = x[5];
+  x[5] = t;
+  t = x[3];
+  x[3] = x[4];
+  x[4] = t;
 }
 
 uint64_t intrev64(uint64_t v) {
-    memrev64(&v);
-    return v;
+  memrev64(&v);
+  return v;
 }
 
-
 /* Set dictionary type. Keys are SDS strings, values are not used. */
 dictType setDictType = {
     dictSdsHash,       /* hash function */
@@ -147,11 +144,11 @@ dictType zsetDictType = {
 
 /* Hash type hash table (note that small hashes are represented with listpacks) */
 dictType hashDictType = {
-    dictSdsHash,                /* hash function */
-    NULL,                       /* key dup */
-    NULL,                       /* val dup */
-    dictSdsKeyCompare,          /* key compare */
-    dictSdsDestructor,          /* key destructor */
-    dictSdsDestructor,          /* val destructor */
-    NULL                        /* allow to expand */
+    dictSdsHash,       /* hash function */
+    NULL,              /* key dup */
+    NULL,              /* val dup */
+    dictSdsKeyCompare, /* key compare */
+    dictSdsDestructor, /* key destructor */
+    dictSdsDestructor, /* val destructor */
+    NULL               /* allow to expand */
 };

src/redis/redis_aux.h

@@ -4,35 +4,34 @@
 #include "dict.h"
 #include "sds.h"
 
-#define HASHTABLE_MIN_FILL        10      /* Minimal hash table fill 10% */
-#define HASHTABLE_MAX_LOAD_FACTOR 1.618   /* Maximum hash table load factor. */
+#define HASHTABLE_MIN_FILL 10           /* Minimal hash table fill 10% */
+#define HASHTABLE_MAX_LOAD_FACTOR 1.618 /* Maximum hash table load factor. */
 
 /* Redis maxmemory strategies. Instead of using just incremental number
  * for this defines, we use a set of flags so that testing for certain
  * properties common to multiple policies is faster. */
-#define MAXMEMORY_FLAG_LRU (1<<0)
-#define MAXMEMORY_FLAG_LFU (1<<1)
-#define MAXMEMORY_FLAG_ALLKEYS (1<<2)
-#define MAXMEMORY_FLAG_NO_SHARED_INTEGERS  (MAXMEMORY_FLAG_LRU|MAXMEMORY_FLAG_LFU)
+#define MAXMEMORY_FLAG_LRU (1 << 0)
+#define MAXMEMORY_FLAG_LFU (1 << 1)
+#define MAXMEMORY_FLAG_ALLKEYS (1 << 2)
+#define MAXMEMORY_FLAG_NO_SHARED_INTEGERS (MAXMEMORY_FLAG_LRU | MAXMEMORY_FLAG_LFU)
 
 #define LFU_INIT_VAL 5
 
-#define MAXMEMORY_VOLATILE_LRU ((0<<8)|MAXMEMORY_FLAG_LRU)
-#define MAXMEMORY_VOLATILE_LFU ((1<<8)|MAXMEMORY_FLAG_LFU)
-#define MAXMEMORY_VOLATILE_TTL (2<<8)
-#define MAXMEMORY_VOLATILE_RANDOM (3<<8)
-#define MAXMEMORY_ALLKEYS_LRU ((4<<8)|MAXMEMORY_FLAG_LRU|MAXMEMORY_FLAG_ALLKEYS)
-#define MAXMEMORY_ALLKEYS_LFU ((5<<8)|MAXMEMORY_FLAG_LFU|MAXMEMORY_FLAG_ALLKEYS)
-#define MAXMEMORY_ALLKEYS_RANDOM ((6<<8)|MAXMEMORY_FLAG_ALLKEYS)
-#define MAXMEMORY_NO_EVICTION (7<<8)
-
+#define MAXMEMORY_VOLATILE_LRU ((0 << 8) | MAXMEMORY_FLAG_LRU)
+#define MAXMEMORY_VOLATILE_LFU ((1 << 8) | MAXMEMORY_FLAG_LFU)
+#define MAXMEMORY_VOLATILE_TTL (2 << 8)
+#define MAXMEMORY_VOLATILE_RANDOM (3 << 8)
+#define MAXMEMORY_ALLKEYS_LRU ((4 << 8) | MAXMEMORY_FLAG_LRU | MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_ALLKEYS_LFU ((5 << 8) | MAXMEMORY_FLAG_LFU | MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_ALLKEYS_RANDOM ((6 << 8) | MAXMEMORY_FLAG_ALLKEYS)
+#define MAXMEMORY_NO_EVICTION (7 << 8)
 
 #define CONFIG_RUN_ID_SIZE 40U
 
 #define EVPOOL_CACHED_SDS_SIZE 255
 #define EVPOOL_SIZE 16
 
-int htNeedsResize(dict *dict);  // moved from server.cc
+int htNeedsResize(dict* dict);  // moved from server.cc
 
 /* Hash table types */
 extern dictType zsetDictType;
@@ -52,39 +51,35 @@ extern dictType hashDictType;
  * Empty entries have the key pointer set to NULL. */
 
 struct evictionPoolEntry {
-    unsigned long long idle;    /* Object idle time (inverse frequency for LFU) */
-    sds key;                    /* Key name. */
-    sds cached;                 /* Cached SDS object for key name. */
-    int dbid;                   /* Key DB number. */
+  unsigned long long idle; /* Object idle time (inverse frequency for LFU) */
+  sds key;                 /* Key name. */
+  sds cached;              /* Cached SDS object for key name. */
+  int dbid;                /* Key DB number. */
 };
 
-uint64_t dictSdsHash(const void *key);
-int dictSdsKeyCompare(dict *privdata, const void *key1, const void *key2);
-void dictSdsDestructor(dict *privdata, void *val);
-size_t sdsZmallocSize(sds s) ;
+uint64_t dictSdsHash(const void* key);
+int dictSdsKeyCompare(dict* privdata, const void* key1, const void* key2);
+void dictSdsDestructor(dict* privdata, void* val);
+size_t sdsZmallocSize(sds s);
 
 typedef struct ServerStub {
-    int rdb_compression;
-
-    int lfu_decay_time;             /* LFU counter decay factor. */
-    /* should not be used. Use FLAGS_list_max_ziplist_size and FLAGS_list_compress_depth instead. */
-    // int list_compress_depth;
-    // int list_max_ziplist_size;
+  int lfu_decay_time; /* LFU counter decay factor. */
+  /* should not be used. Use FLAGS_list_max_ziplist_size and FLAGS_list_compress_depth instead. */
+  // int list_compress_depth;
+  // int list_max_ziplist_size;
 
-    // unused - left so that object.c will compile.
-    int maxmemory_policy;           /* Policy for key eviction */
+  // unused - left so that object.c will compile.
+  int maxmemory_policy; /* Policy for key eviction */
 
-    unsigned long page_size;
-    size_t hash_max_listpack_entries,
-           hash_max_listpack_value;
-    size_t zset_max_listpack_entries;
-    size_t zset_max_listpack_value;
+  unsigned long page_size;
+  size_t hash_max_listpack_entries, hash_max_listpack_value;
+  size_t zset_max_listpack_entries;
+  size_t zset_max_listpack_value;
 
-    size_t stream_node_max_bytes;
-    long long stream_node_max_entries;
+  size_t stream_node_max_bytes;
+  long long stream_node_max_entries;
 } Server;
 
-
 extern Server server;
 
 void InitRedisTables();

src/server/CMakeLists.txt

@@ -21,7 +21,7 @@ add_library(dragonfly_lib  channel_slice.cc command_registry.cc
             zset_family.cc version.cc bitops_family.cc container_utils.cc)
 
 cxx_link(dragonfly_lib dfly_transaction dfly_facade redis_lib strings_lib html_lib
-         absl::random_random TRDP::jsoncons)
+         absl::random_random TRDP::jsoncons zstd)
 
 add_library(dfly_test_lib test_utils.cc)
 cxx_link(dfly_test_lib dragonfly_lib epoll_fiber_lib facade_test gtest_main_ext)

src/server/generic_family.cc

@@ -26,6 +26,7 @@ extern "C" {
 
 ABSL_FLAG(uint32_t, dbnum, 16, "Number of databases");
 ABSL_FLAG(uint32_t, keys_output_limit, 8192, "Maximum number of keys output by keys command");
+ABSL_DECLARE_FLAG(int, compression_mode);
 
 namespace dfly {
 using namespace std;
@@ -429,7 +430,8 @@ OpResult<std::string> OpDump(const OpArgs& op_args, string_view key) {
   if (IsValid(it)) {
     DVLOG(1) << "Dump: key '" << key << "' successfully found, going to dump it";
     std::unique_ptr<::io::StringSink> sink = std::make_unique<::io::StringSink>();
-    RdbSerializer serializer(sink.get());
+    int compression_mode = absl::GetFlag(FLAGS_compression_mode);
+    RdbSerializer serializer(sink.get(), compression_mode != 0);
 
     // According to Redis code we need to
     // 1. Save the value itself - without the key

src/server/rdb_extensions.h

@@ -10,3 +10,5 @@
 // to notify that it finished streaming static data and is ready
 // to switch to the stable state replication phase.
 const uint8_t RDB_OPCODE_FULLSYNC_END = 200;
+const uint8_t RDB_OPCODE_COMPRESSED_BLOB_START = 201;
+const uint8_t RDB_OPCODE_COMPRESSED_BLOB_END = 202;