From 3dffb8e21ed9066caebb6a95d1ac0a58157887c7 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 28 Feb 2011 10:01:04 +0100
Subject: [PATCH] save zipmap encoded hashes as blobs. Work in progress.

---
 src/rdb.c    | 32 ++++++++++++++++++--------------
 src/redis.h  |  2 ++
 src/zipmap.c | 10 +++++++---
 src/zipmap.h |  3 ++-
 4 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/src/rdb.c b/src/rdb.c
index a9e4b1a0..3d187948 100644
--- a/src/rdb.c
+++ b/src/rdb.c
@@ -139,7 +139,7 @@ writeerr:
 }
 
 /* Save a string objet as [len][data] on disk. If the object is a string
- * representation of an integer value we try to safe it in a special form */
+ * representation of an integer value we try to save it in a special form */
 int rdbSaveRawString(FILE *fp, unsigned char *s, size_t len) {
     int enclen;
     int n, nwritten = 0;
@@ -385,20 +385,10 @@ int rdbSaveObject(FILE *fp, robj *o) {
     } else if (o->type == REDIS_HASH) {
         /* Save a hash value */
         if (o->encoding == REDIS_ENCODING_ZIPMAP) {
-            unsigned char *p = zipmapRewind(o->ptr);
-            unsigned int count = zipmapLen(o->ptr);
-            unsigned char *key, *val;
-            unsigned int klen, vlen;
+            size_t l = zipmapBlobLen((unsigned char*)o->ptr);
 
-            if ((n = rdbSaveLen(fp,count)) == -1) return -1;
+            if ((n = rdbSaveRawString(fp,o->ptr,l)) == -1) return -1;
             nwritten += n;
-
-            while((p = zipmapNext(p,&key,&klen,&val,&vlen)) != NULL) {
-                if ((n = rdbSaveRawString(fp,key,klen)) == -1) return -1;
-                nwritten += n;
-                if ((n = rdbSaveRawString(fp,val,vlen)) == -1) return -1;
-                nwritten += n;
-            }
         } else {
             dictIterator *di = dictGetIterator(o->ptr);
             dictEntry *de;
@@ -495,8 +485,12 @@ int rdbSave(char *filename) {
              * handling if the value is swapped out. */
             if (!server.vm_enabled || o->storage == REDIS_VM_MEMORY ||
                                       o->storage == REDIS_VM_SWAPPING) {
+                int otype = o->type;
+
+                if (otype == REDIS_HASH && o->encoding == REDIS_ENCODING_ZIPMAP)
+                    otype = REDIS_HASH_ZIPMAP;
                 /* Save type, key, value */
-                if (rdbSaveType(fp,o->type) == -1) goto werr;
+                if (rdbSaveType(fp,otype) == -1) goto werr;
                 if (rdbSaveStringObject(fp,&key) == -1) goto werr;
                 if (rdbSaveObject(fp,o) == -1) goto werr;
             } else {
@@ -890,6 +884,16 @@ robj *rdbLoadObject(int type, FILE *fp) {
                 dictAdd((dict*)o->ptr,key,val);
             }
         }
+    } else if (type == REDIS_HASH_ZIPMAP) {
+        robj *aux = rdbLoadStringObject(fp);
+
+        if (aux == NULL) return NULL;
+        o = createHashObject();
+        o->encoding = REDIS_ENCODING_ZIPMAP;
+        o->ptr = zmalloc(sdslen(aux->ptr));
+        memcpy(o->ptr,aux->ptr,sdslen(aux->ptr));
+        decrRefCount(aux);
+        /* FIXME: conver the object if needed */
     } else {
         redisPanic("Unknown object type");
     }
diff --git a/src/redis.h b/src/redis.h
index 5940bb90..6b03d626 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -70,6 +70,8 @@
 #define REDIS_ZSET 3
 #define REDIS_HASH 4
 #define REDIS_VMPOINTER 8
+/* Object types only used for persistence in .rdb files */
+#define REDIS_HASH_ZIPMAP 9
 
 /* Objects encoding. Some kind of objects like Strings and Hashes can be
  * internally represented in multiple ways. The 'encoding' field of the object
diff --git a/src/zipmap.c b/src/zipmap.c
index cc7586cf..9f0fc718 100644
--- a/src/zipmap.c
+++ b/src/zipmap.c
@@ -80,6 +80,7 @@
 #include <string.h>
 #include <assert.h>
 #include "zmalloc.h"
+#include "endian.h"
 
 #define ZIPMAP_BIGLEN 254
 #define ZIPMAP_END 255
@@ -108,6 +109,7 @@ static unsigned int zipmapDecodeLength(unsigned char *p) {
 
     if (len < ZIPMAP_BIGLEN) return len;
     memcpy(&len,p+1,sizeof(unsigned int));
+    memrev32ifbe(&len);
     return len;
 }
 
@@ -123,6 +125,7 @@ static unsigned int zipmapEncodeLength(unsigned char *p, unsigned int len) {
         } else {
             p[0] = ZIPMAP_BIGLEN;
             memcpy(p+1,&len,sizeof(len));
+            memrev32ifbe(p+1);
             return 1+sizeof(len);
         }
     }
@@ -360,15 +363,16 @@ unsigned int zipmapLen(unsigned char *zm) {
     return len;
 }
 
-/* Return zipmap size in bytes. */
-size_t zipmapSize(unsigned char *zm) {
+/* Return the raw size in bytes of a zipmap, so that we can serialize
+ * the zipmap on disk (or everywhere is needed) just writing the returned
+ * amount of bytes of the C array starting at the zipmap pointer. */
+size_t zipmapBlobLen(unsigned char *zm) {
     unsigned int totlen;
     zipmapLookupRaw(zm,NULL,0,&totlen);
     return totlen;
 }
 
 #ifdef ZIPMAP_TEST_MAIN
-
 void zipmapRepr(unsigned char *p) {
     unsigned int l;
 
diff --git a/src/zipmap.h b/src/zipmap.h
index ae800030..acb25d67 100644
--- a/src/zipmap.h
+++ b/src/zipmap.h
@@ -43,6 +43,7 @@ unsigned char *zipmapNext(unsigned char *zm, unsigned char **key, unsigned int *
 int zipmapGet(unsigned char *zm, unsigned char *key, unsigned int klen, unsigned char **value, unsigned int *vlen);
 int zipmapExists(unsigned char *zm, unsigned char *key, unsigned int klen);
 unsigned int zipmapLen(unsigned char *zm);
-size_t zipmapSize(unsigned char *zm);
+size_t zipmapBlobLen(unsigned char *zm);
+void zipmapRepr(unsigned char *p);
 
 #endif