String value unsharing refactored into proper function.

All the Redis functions that need to modify the string value of a key in
a destructive way (APPEND, SETBIT, SETRANGE, ...) require to make the
object unshared (if refcount > 1) and encoded in raw format (if encoding
is not already REDIS_ENCODING_RAW).

This was cut & pasted many times in multiple places of the code. This
commit puts the small logic needed into a function called
dbUnshareStringValue().

1 files changed, 2 insertions, 14 deletions

diff --git a/src/t_string.c b/src/t_string.c
index 3645ae7c5..41e4b3b71 100644
--- a/src/t_string.c
+++ b/src/t_string.c
@@ -215,12 +215,7 @@ void setrangeCommand(redisClient *c) {
             return;
 
         /* Create a copy when the object is shared or encoded. */
-        if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
-            robj *decoded = getDecodedObject(o);
-            o = createRawStringObject(decoded->ptr, sdslen(decoded->ptr));
-            decrRefCount(decoded);
-            dbOverwrite(c->db,c->argv[1],o);
-        }
+        o = dbUnshareStringValue(c->db,c->argv[1],o);
     }
 
     if (sdslen(value) > 0) {
@@ -433,15 +428,8 @@ void appendCommand(redisClient *c) {
         if (checkStringLength(c,totlen) != REDIS_OK)
             return;
 
-        /* If the object is shared or encoded, we have to make a copy */
-        if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
-            robj *decoded = getDecodedObject(o);
-            o = createRawStringObject(decoded->ptr, sdslen(decoded->ptr));
-            decrRefCount(decoded);
-            dbOverwrite(c->db,c->argv[1],o);
-        }
-
         /* Append the value */
+        o = dbUnshareStringValue(c->db,c->argv[1],o);
         o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
         totlen = sdslen(o->ptr);
     }