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Speed up index file writing by chunking it nicely.
No point in making 17,000 small writes when you can make just a couple of hundred nice 8kB writes instead and save a lot of time.
This commit is contained in:
parent
706bc531a1
commit
4990aadc4c
43
read-cache.c
43
read-cache.c
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@ -227,6 +227,42 @@ int read_cache(void)
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return error("verify header failed");
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}
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#define WRITE_BUFFER_SIZE 8192
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static char write_buffer[WRITE_BUFFER_SIZE];
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static unsigned long write_buffer_len;
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static int ce_write(int fd, void *data, unsigned int len)
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{
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while (len) {
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unsigned int buffered = write_buffer_len;
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unsigned int partial = WRITE_BUFFER_SIZE - buffered;
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if (partial > len)
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partial = len;
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memcpy(write_buffer + buffered, data, partial);
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buffered += partial;
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if (buffered == WRITE_BUFFER_SIZE) {
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if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE)
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return -1;
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buffered = 0;
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}
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write_buffer_len = buffered;
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len -= partial;
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data += partial;
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}
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return 0;
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}
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static int ce_flush(int fd)
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{
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unsigned int left = write_buffer_len;
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if (left) {
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write_buffer_len = 0;
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if (write(fd, write_buffer, left) != left)
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return -1;
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}
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return 0;
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}
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int write_cache(int newfd, struct cache_entry **cache, int entries)
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{
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SHA_CTX c;
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@ -246,14 +282,13 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
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}
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SHA1_Final(hdr.sha1, &c);
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if (write(newfd, &hdr, sizeof(hdr)) != sizeof(hdr))
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if (ce_write(newfd, &hdr, sizeof(hdr)) < 0)
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return -1;
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for (i = 0; i < entries; i++) {
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struct cache_entry *ce = cache[i];
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int size = ce_size(ce);
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if (write(newfd, ce, size) != size)
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if (ce_write(newfd, ce, ce_size(ce)) < 0)
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return -1;
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}
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return 0;
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return ce_flush(newfd);
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}
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