Commit 8ad21e6b authored by Nikias Bassen's avatar Nikias Bassen

xplist: Improve writing of large PLIST_DATA nodes by growing buffer in advance

Instead of letting the buffer grow by just the amount of bytes currently
transformed to base64 - which is basically line by line - we now calculate
the size of the output blob in advance and grow the buffer accordingly.
This will reduce the amount of reallocs to just one, which is especially
important for large data blobs.
While this is a general improvement for all platforms, it is on platforms
like Windows where realloc() can be REALLY slow; converting a 20mb blob to
XML can easily take up to a minute (due to the several hundred thousand
calls to realloc()). With this commit, it will be fast again.
parent 32ee5213
......@@ -41,15 +41,20 @@ void byte_array_free(bytearray_t *ba)
free(ba);
}
void byte_array_grow(bytearray_t *ba, size_t amount)
{
size_t increase = (amount > PAGE_SIZE) ? (amount+(PAGE_SIZE-1)) & (~(PAGE_SIZE-1)) : PAGE_SIZE;
ba->data = realloc(ba->data, ba->capacity + increase);
ba->capacity += increase;
}
void byte_array_append(bytearray_t *ba, void *buf, size_t len)
{
if (!ba || !ba->data || (len <= 0)) return;
size_t remaining = ba->capacity-ba->len;
if (len > remaining) {
size_t needed = len - remaining;
size_t increase = (needed > PAGE_SIZE) ? (needed+(PAGE_SIZE-1)) & (~(PAGE_SIZE-1)) : PAGE_SIZE;
ba->data = realloc(ba->data, ba->capacity + increase);
ba->capacity += increase;
byte_array_grow(ba, needed);
}
memcpy(((char*)ba->data) + ba->len, buf, len);
ba->len += len;
......
......@@ -30,6 +30,7 @@ typedef struct bytearray_t {
bytearray_t *byte_array_new();
void byte_array_free(bytearray_t *ba);
void byte_array_grow(bytearray_t *ba, size_t amount);
void byte_array_append(bytearray_t *ba, void *buf, size_t len);
#endif
......@@ -28,6 +28,7 @@ typedef struct bytearray_t strbuf_t;
#define str_buf_new() byte_array_new()
#define str_buf_free(__ba) byte_array_free(__ba)
#define str_buf_grow(__ba, __am) byte_array_grow(__ba, __am)
#define str_buf_append(__ba, __str, __len) byte_array_append(__ba, (void*)(__str), __len)
#endif
......@@ -294,6 +294,7 @@ static void node_to_xml(node_t* node, bytearray_t **outbuf, uint32_t depth)
uint32_t maxread = ((76 - indent*8) / 4) * 3;
size_t count = 0;
size_t b64count = 0;
str_buf_grow(*outbuf, (node_data->length / 3 * 4) + 4 + (((node_data->length / maxread) + 1) * (indent+1)));
while (j < node_data->length) {
for (i = 0; i < indent; i++) {
str_buf_append(*outbuf, "\t", 1);
......
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