mirror of
https://github.com/git/git
synced 2024-08-27 19:49:21 +00:00
binary diff: further updates.
This updates the user interface and generated diff data format. * "diff --binary" is used to signal that we want an e-mailable binary patch. It implies --full-index and -p. * "apply --allow-binary-replacement" acquired a short synonym "apply --binary". * After the "GIT binary patch\n" header line there is a token to record which binary patch mechanism was used, so that we can extend it later. Currently there are two mechanisms defined: "literal" and "delta". The former records the deflated postimage and the latter records the deflated delta from the preimage to postimage. For purely implementation convenience, I added the deflated length after these "literal/delta" tokens (otherwise the decoding side needs to guess and reallocate the buffer while inflating). Improvement patches are very welcomed. Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
parent
051308f6e9
commit
0660626caf
130
apply.c
130
apply.c
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@ -114,6 +114,9 @@ struct patch {
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char *new_name, *old_name, *def_name;
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unsigned int old_mode, new_mode;
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int is_rename, is_copy, is_new, is_delete, is_binary;
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#define BINARY_DELTA_DEFLATED 1
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#define BINARY_LITERAL_DEFLATED 2
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unsigned long deflate_origlen;
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int lines_added, lines_deleted;
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int score;
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struct fragment *fragments;
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@ -969,9 +972,11 @@ static inline int metadata_changes(struct patch *patch)
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static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
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{
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/* We have read "GIT binary patch\n"; what follows is a
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* sequence of 'length-byte' followed by base-85 encoded
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* delta data.
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/* We have read "GIT binary patch\n"; what follows is a line
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* that says the patch method (currently, either "deflated
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* literal" or "deflated delta") and the length of data before
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* deflating; a sequence of 'length-byte' followed by base-85
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* encoded data follows.
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*
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* Each 5-byte sequence of base-85 encodes up to 4 bytes,
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* and we would limit the patch line to 66 characters,
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@ -982,11 +987,27 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
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*/
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int llen, used;
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struct fragment *fragment;
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char *delta = NULL;
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char *data = NULL;
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patch->is_binary = 1;
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patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
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used = 0;
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/* Grab the type of patch */
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llen = linelen(buffer, size);
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used = llen;
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linenr++;
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if (!strncmp(buffer, "delta ", 6)) {
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patch->is_binary = BINARY_DELTA_DEFLATED;
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patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
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}
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else if (!strncmp(buffer, "literal ", 8)) {
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patch->is_binary = BINARY_LITERAL_DEFLATED;
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patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
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}
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else
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return error("unrecognized binary patch at line %d: %.*s",
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linenr-1, llen-1, buffer);
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buffer += llen;
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while (1) {
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int byte_length, max_byte_length, newsize;
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llen = linelen(buffer, size);
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@ -1015,8 +1036,8 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
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byte_length <= max_byte_length - 4)
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goto corrupt;
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newsize = fragment->size + byte_length;
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delta = xrealloc(delta, newsize);
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if (decode_85(delta + fragment->size,
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data = xrealloc(data, newsize);
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if (decode_85(data + fragment->size,
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buffer + 1,
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byte_length))
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goto corrupt;
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@ -1024,7 +1045,7 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
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buffer += llen;
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size -= llen;
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}
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fragment->patch = delta;
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fragment->patch = data;
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return used;
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corrupt:
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return error("corrupt binary patch at line %d: %.*s",
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@ -1425,6 +1446,61 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
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return offset;
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}
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static char *inflate_it(const void *data, unsigned long size,
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unsigned long inflated_size)
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{
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z_stream stream;
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void *out;
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int st;
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memset(&stream, 0, sizeof(stream));
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stream.next_in = (unsigned char *)data;
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stream.avail_in = size;
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stream.next_out = out = xmalloc(inflated_size);
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stream.avail_out = inflated_size;
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inflateInit(&stream);
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st = inflate(&stream, Z_FINISH);
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if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
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free(out);
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return NULL;
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}
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return out;
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}
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static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
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{
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unsigned long dst_size;
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struct fragment *fragment = patch->fragments;
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void *data;
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void *result;
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data = inflate_it(fragment->patch, fragment->size,
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patch->deflate_origlen);
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if (!data)
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return error("corrupt patch data");
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switch (patch->is_binary) {
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case BINARY_DELTA_DEFLATED:
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result = patch_delta(desc->buffer, desc->size,
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data,
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patch->deflate_origlen,
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&dst_size);
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free(desc->buffer);
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desc->buffer = result;
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free(data);
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break;
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case BINARY_LITERAL_DEFLATED:
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free(desc->buffer);
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desc->buffer = data;
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dst_size = patch->deflate_origlen;
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break;
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}
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if (!desc->buffer)
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return -1;
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desc->size = desc->alloc = dst_size;
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return 0;
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}
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static int apply_binary(struct buffer_desc *desc, struct patch *patch)
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{
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const char *name = patch->old_name ? patch->old_name : patch->new_name;
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@ -1466,18 +1542,20 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
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"'%s' but it is not empty", name);
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}
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if (desc->buffer) {
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get_sha1_hex(patch->new_sha1_prefix, sha1);
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if (!memcmp(sha1, null_sha1, 20)) {
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free(desc->buffer);
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desc->alloc = desc->size = 0;
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}
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get_sha1_hex(patch->new_sha1_prefix, sha1);
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if (!memcmp(sha1, null_sha1, 20))
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desc->buffer = NULL;
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return 0; /* deletion patch */
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}
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if (has_sha1_file(sha1)) {
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/* We already have the postimage */
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char type[10];
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unsigned long size;
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free(desc->buffer);
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desc->buffer = read_sha1_file(sha1, type, &size);
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if (!desc->buffer)
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return error("the necessary postimage %s for "
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@ -1486,28 +1564,13 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
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desc->alloc = desc->size = size;
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}
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else {
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char type[10];
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unsigned long src_size, dst_size;
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void *src;
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get_sha1_hex(patch->old_sha1_prefix, sha1);
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src = read_sha1_file(sha1, type, &src_size);
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if (!src)
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return error("the necessary preimage %s for "
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"'%s' cannot be read",
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patch->old_sha1_prefix, name);
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/* patch->fragment->patch has the delta data and
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* we should apply it to the preimage.
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/* We have verified desc matches the preimage;
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* apply the patch data to it, which is stored
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* in the patch->fragments->{patch,size}.
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*/
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desc->buffer = patch_delta(src, src_size,
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(void*) patch->fragments->patch,
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patch->fragments->size,
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&dst_size);
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if (!desc->buffer)
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if (apply_binary_fragment(desc, patch))
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return error("binary patch does not apply to '%s'",
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name);
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desc->size = desc->alloc = dst_size;
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/* verify that the result matches */
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write_sha1_file_prepare(desc->buffer, desc->size, blob_type,
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@ -2102,7 +2165,8 @@ int main(int argc, char **argv)
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diffstat = 1;
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continue;
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}
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if (!strcmp(arg, "--allow-binary-replacement")) {
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if (!strcmp(arg, "--allow-binary-replacement") ||
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!strcmp(arg, "--binary")) {
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allow_binary_replacement = 1;
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continue;
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}
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134
base85.c
Normal file
134
base85.c
Normal file
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@ -0,0 +1,134 @@
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#include "cache.h"
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#undef DEBUG_85
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#ifdef DEBUG_85
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#define say(a) fprintf(stderr, a)
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#define say1(a,b) fprintf(stderr, a, b)
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#define say2(a,b,c) fprintf(stderr, a, b, c)
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#else
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#define say(a) do {} while(0)
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#define say1(a,b) do {} while(0)
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#define say2(a,b,c) do {} while(0)
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#endif
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static const char en85[] = {
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'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
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'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
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'U', 'V', 'W', 'X', 'Y', 'Z',
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
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'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
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'u', 'v', 'w', 'x', 'y', 'z',
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'!', '#', '$', '%', '&', '(', ')', '*', '+', '-',
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';', '<', '=', '>', '?', '@', '^', '_', '`', '{',
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'|', '}', '~'
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};
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static char de85[256];
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static void prep_base85(void)
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{
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int i;
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if (de85['Z'])
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return;
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for (i = 0; i < ARRAY_SIZE(en85); i++) {
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int ch = en85[i];
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de85[ch] = i + 1;
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}
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}
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int decode_85(char *dst, char *buffer, int len)
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{
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prep_base85();
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say2("decode 85 <%.*s>", len/4*5, buffer);
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while (len) {
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unsigned acc = 0;
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int cnt;
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for (cnt = 0; cnt < 5; cnt++, buffer++) {
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int ch = *((unsigned char *)buffer);
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int de = de85[ch];
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if (!de)
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return error("invalid base85 alphabet %c", ch);
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de--;
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if (cnt == 4) {
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/*
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* Detect overflow. The largest
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* 5-letter possible is "|NsC0" to
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* encode 0xffffffff, and "|NsC" gives
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* 0x03030303 at this point (i.e.
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* 0xffffffff = 0x03030303 * 85).
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*/
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if (0x03030303 < acc ||
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(0x03030303 == acc && de))
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error("invalid base85 sequence %.5s",
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buffer-3);
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}
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acc = acc * 85 + de;
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say1(" <%08x>", acc);
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}
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say1(" %08x", acc);
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for (cnt = 0; cnt < 4 && len; cnt++, len--) {
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*dst++ = (acc >> 24) & 0xff;
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acc = acc << 8;
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}
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}
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say("\n");
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return 0;
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}
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void encode_85(char *buf, unsigned char *data, int bytes)
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{
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prep_base85();
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say("encode 85");
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while (bytes) {
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unsigned acc = 0;
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int cnt;
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for (cnt = 0; cnt < 4 && bytes; cnt++, bytes--) {
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int ch = *data++;
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acc |= ch << ((3-cnt)*8);
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}
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say1(" %08x", acc);
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for (cnt = 0; cnt < 5; cnt++) {
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int val = acc % 85;
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acc /= 85;
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buf[4-cnt] = en85[val];
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}
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buf += 5;
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}
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say("\n");
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*buf = 0;
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}
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#ifdef DEBUG_85
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int main(int ac, char **av)
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{
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char buf[1024];
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if (!strcmp(av[1], "-e")) {
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int len = strlen(av[2]);
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encode_85(buf, av[2], len);
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if (len <= 26) len = len + 'A' - 1;
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else len = len + 'a' - 26 + 1;
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printf("encoded: %c%s\n", len, buf);
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return 0;
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}
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if (!strcmp(av[1], "-d")) {
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int len = *av[2];
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if ('A' <= len && len <= 'Z') len = len - 'A' + 1;
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else len = len - 'a' + 26 + 1;
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decode_85(buf, av[2]+1, len);
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printf("decoded: %.*s\n", len, buf);
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return 0;
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}
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if (!strcmp(av[1], "-t")) {
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char t[4] = { -1,-1,-1,-1 };
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encode_85(buf, t, 4);
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printf("encoded: D%s\n", buf);
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return 0;
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}
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}
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#endif
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1
cache.h
1
cache.h
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@ -365,5 +365,6 @@ extern void setup_pager(void);
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/* base85 */
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int decode_85(char *dst, char *line, int linelen);
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void encode_85(char *buf, unsigned char *data, int bytes);
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#endif /* CACHE_H */
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132
diff.c
132
diff.c
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@ -392,78 +392,78 @@ static void show_stats(struct diffstat_t* data)
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total_files, adds, dels);
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}
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static void *encode_delta_size(void *data, unsigned long size)
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static unsigned char *deflate_it(char *data,
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unsigned long size,
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unsigned long *result_size)
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{
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unsigned char *cp = data;
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*cp++ = size;
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size >>= 7;
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while (size) {
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cp[-1] |= 0x80;
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*cp++ = size;
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size >>= 7;
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}
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return cp;
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}
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int bound;
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unsigned char *deflated;
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z_stream stream;
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static void *safe_diff_delta(const unsigned char *src, unsigned long src_size,
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const unsigned char *dst, unsigned long dst_size,
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unsigned long *delta_size)
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{
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unsigned long bufsize;
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unsigned char *data;
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unsigned char *cp;
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memset(&stream, 0, sizeof(stream));
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deflateInit(&stream, Z_BEST_COMPRESSION);
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bound = deflateBound(&stream, size);
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deflated = xmalloc(bound);
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stream.next_out = deflated;
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stream.avail_out = bound;
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if (src_size && dst_size)
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return diff_delta(src, src_size, dst, dst_size, delta_size, 0);
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/* diff-delta does not like to do delta with empty, so
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* we do that by hand here. Sigh...
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*/
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if (!src_size)
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/* literal copy can be done only 127-byte at a time.
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*/
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bufsize = dst_size + (dst_size / 127) + 40;
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else
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bufsize = 40;
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data = xmalloc(bufsize);
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cp = encode_delta_size(data, src_size);
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cp = encode_delta_size(cp, dst_size);
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if (dst_size) {
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/* copy out literally */
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while (dst_size) {
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int sz = (127 < dst_size) ? 127 : dst_size;
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*cp++ = sz;
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dst_size -= sz;
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while (sz) {
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*cp++ = *dst++;
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sz--;
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}
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}
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}
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*delta_size = (cp - data);
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return data;
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stream.next_in = (unsigned char *)data;
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stream.avail_in = size;
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while (deflate(&stream, Z_FINISH) == Z_OK)
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; /* nothing */
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deflateEnd(&stream);
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*result_size = stream.total_out;
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return deflated;
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}
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static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
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{
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void *delta, *cp;
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void *cp;
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void *delta;
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void *deflated;
|
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void *data;
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unsigned long orig_size;
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unsigned long delta_size;
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unsigned long deflate_size;
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unsigned long data_size;
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printf("GIT binary patch\n");
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delta = safe_diff_delta(one->ptr, one->size,
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two->ptr, two->size,
|
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&delta_size);
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if (!delta)
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die("unable to generate binary diff");
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/* We could do deflated delta, or we could do just deflated two,
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* whichever is smaller.
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*/
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delta = NULL;
|
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deflated = deflate_it(two->ptr, two->size, &deflate_size);
|
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if (one->size && two->size) {
|
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delta = diff_delta(one->ptr, one->size,
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two->ptr, two->size,
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&delta_size, deflate_size);
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if (delta) {
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void *to_free = delta;
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orig_size = delta_size;
|
||||
delta = deflate_it(delta, delta_size, &delta_size);
|
||||
free(to_free);
|
||||
}
|
||||
}
|
||||
|
||||
/* emit delta encoded in base85 */
|
||||
cp = delta;
|
||||
while (delta_size) {
|
||||
int bytes = (52 < delta_size) ? 52 : delta_size;
|
||||
if (delta && delta_size < deflate_size) {
|
||||
printf("delta %lu\n", orig_size);
|
||||
free(deflated);
|
||||
data = delta;
|
||||
data_size = delta_size;
|
||||
}
|
||||
else {
|
||||
printf("literal %lu\n", two->size);
|
||||
free(delta);
|
||||
data = deflated;
|
||||
data_size = deflate_size;
|
||||
}
|
||||
|
||||
/* emit data encoded in base85 */
|
||||
cp = data;
|
||||
while (data_size) {
|
||||
int bytes = (52 < data_size) ? 52 : data_size;
|
||||
char line[70];
|
||||
delta_size -= bytes;
|
||||
data_size -= bytes;
|
||||
if (bytes <= 26)
|
||||
line[0] = bytes + 'A' - 1;
|
||||
else
|
||||
|
@ -473,7 +473,7 @@ static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
|
|||
puts(line);
|
||||
}
|
||||
printf("\n");
|
||||
free(delta);
|
||||
free(data);
|
||||
}
|
||||
|
||||
#define FIRST_FEW_BYTES 8000
|
||||
|
@ -538,7 +538,11 @@ static void builtin_diff(const char *name_a,
|
|||
die("unable to read files to diff");
|
||||
|
||||
if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
|
||||
if (o->full_index)
|
||||
/* Quite common confusing case */
|
||||
if (mf1.size == mf2.size &&
|
||||
!memcmp(mf1.ptr, mf2.ptr, mf1.size))
|
||||
goto free_ab_and_return;
|
||||
if (o->binary)
|
||||
emit_binary_diff(&mf1, &mf2);
|
||||
else
|
||||
printf("Binary files %s and %s differ\n",
|
||||
|
@ -1239,6 +1243,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
|
|||
options->rename_limit = strtoul(arg+2, NULL, 10);
|
||||
else if (!strcmp(arg, "--full-index"))
|
||||
options->full_index = 1;
|
||||
else if (!strcmp(arg, "--binary")) {
|
||||
options->output_format = DIFF_FORMAT_PATCH;
|
||||
options->full_index = options->binary = 1;
|
||||
}
|
||||
else if (!strcmp(arg, "--name-only"))
|
||||
options->output_format = DIFF_FORMAT_NAME;
|
||||
else if (!strcmp(arg, "--name-status"))
|
||||
|
|
Loading…
Reference in a new issue