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SDS: use type 8 if we are likely to append to the string.
When empty strings are created, or when sdsMakeRoomFor() is called, we are likely into an appending pattern. Use at least type 8 SDS strings since TYPE 5 does not remember the free allocation size and requires to call sdsMakeRoomFor() at every new piece appended.
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parent
cf68f4ee6a
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11
src/sds.c
11
src/sds.c
@ -80,6 +80,9 @@ sds sdsnewlen(const void *init, size_t initlen) {
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void *sh;
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sds s;
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char type = sdsReqType(initlen);
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/* Empty strings are usually created in order to append. Use type 8
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* since type 5 is not good at this. */
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if (type == SDS_TYPE_5 && initlen == 0) type = SDS_TYPE_8;
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int hdrlen = sdsHdrSize(type);
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unsigned char *fp; /* flags pointer. */
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@ -193,7 +196,9 @@ sds sdsMakeRoomFor(sds s, size_t addlen) {
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char type, oldtype = s[-1] & SDS_TYPE_MASK;
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int hdrlen;
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/* Return ASAP if there is enough space left. */
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if (avail >= addlen) return s;
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len = sdslen(s);
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sh = (char*)s-sdsHdrSize(oldtype);
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newlen = (len+addlen);
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@ -203,6 +208,12 @@ sds sdsMakeRoomFor(sds s, size_t addlen) {
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newlen += SDS_MAX_PREALLOC;
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type = sdsReqType(newlen);
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/* Don't use type 5: the user is appending to the string and type 5 is
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* not able to remember empty space, so sdsMakeRoomFor() must be called
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* at every appending operation. */
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if (type == SDS_TYPE_5) type = SDS_TYPE_8;
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hdrlen = sdsHdrSize(type);
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if (oldtype==type) {
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newsh = zrealloc(sh, hdrlen+newlen+1);
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