git-apply --binary: clean up and prepare for --reverse
This cleans up the implementation of "git-apply --binary", and implements reverse application of binary patches (when git-diff is converted to emit reversible binary patches). Earlier, the types of encoding (either deflated literal or deflated delta) were stored in is_binary field in struct patch, which meant that we cannot store more than one fragment that differ in the encoding for a patch. This moves the information to a field in struct fragment that is otherwise unused for binary patches, and makes it possible to hang two (or more, but two is enough) hunks for a binary patch. The original "binary patch" output from git-diff is internally parsed into an "is_binary" patch with one fragment. Upcoming reversible binary patch output will have two fragments, the first one being the forward patch and the second one the reverse patch. Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Junio C Hamano
parent
d1b9944db8
commit
3cd4f5e8eb
200
builtin-apply.c
200
builtin-apply.c
@ -109,6 +109,13 @@ static int max_change, max_len;
|
||||
*/
|
||||
static int linenr = 1;
|
||||
|
||||
/*
|
||||
* This represents one "hunk" from a patch, starting with
|
||||
* "@@ -oldpos,oldlines +newpos,newlines @@" marker. The
|
||||
* patch text is pointed at by patch, and its byte length
|
||||
* is stored in size. leading and trailing are the number
|
||||
* of context lines.
|
||||
*/
|
||||
struct fragment {
|
||||
unsigned long leading, trailing;
|
||||
unsigned long oldpos, oldlines;
|
||||
@ -118,12 +125,19 @@ struct fragment {
|
||||
struct fragment *next;
|
||||
};
|
||||
|
||||
/*
|
||||
* When dealing with a binary patch, we reuse "leading" field
|
||||
* to store the type of the binary hunk, either deflated "delta"
|
||||
* or deflated "literal".
|
||||
*/
|
||||
#define binary_patch_method leading
|
||||
#define BINARY_DELTA_DEFLATED 1
|
||||
#define BINARY_LITERAL_DEFLATED 2
|
||||
|
||||
struct patch {
|
||||
char *new_name, *old_name, *def_name;
|
||||
unsigned int old_mode, new_mode;
|
||||
int is_rename, is_copy, is_new, is_delete, is_binary;
|
||||
#define BINARY_DELTA_DEFLATED 1
|
||||
#define BINARY_LITERAL_DEFLATED 2
|
||||
unsigned long deflate_origlen;
|
||||
int lines_added, lines_deleted;
|
||||
int score;
|
||||
@ -979,43 +993,70 @@ static inline int metadata_changes(struct patch *patch)
|
||||
patch->old_mode != patch->new_mode);
|
||||
}
|
||||
|
||||
static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
|
||||
static char *inflate_it(const void *data, unsigned long size,
|
||||
unsigned long inflated_size)
|
||||
{
|
||||
/* We have read "GIT binary patch\n"; what follows is a line
|
||||
* that says the patch method (currently, either "deflated
|
||||
* literal" or "deflated delta") and the length of data before
|
||||
* deflating; a sequence of 'length-byte' followed by base-85
|
||||
* encoded data follows.
|
||||
z_stream stream;
|
||||
void *out;
|
||||
int st;
|
||||
|
||||
memset(&stream, 0, sizeof(stream));
|
||||
|
||||
stream.next_in = (unsigned char *)data;
|
||||
stream.avail_in = size;
|
||||
stream.next_out = out = xmalloc(inflated_size);
|
||||
stream.avail_out = inflated_size;
|
||||
inflateInit(&stream);
|
||||
st = inflate(&stream, Z_FINISH);
|
||||
if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
|
||||
free(out);
|
||||
return NULL;
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
||||
static struct fragment *parse_binary_hunk(char **buf_p,
|
||||
unsigned long *sz_p,
|
||||
int *status_p,
|
||||
int *used_p)
|
||||
{
|
||||
/* Expect a line that begins with binary patch method ("literal"
|
||||
* or "delta"), followed by the length of data before deflating.
|
||||
* a sequence of 'length-byte' followed by base-85 encoded data
|
||||
* should follow, terminated by a newline.
|
||||
*
|
||||
* Each 5-byte sequence of base-85 encodes up to 4 bytes,
|
||||
* and we would limit the patch line to 66 characters,
|
||||
* so one line can fit up to 13 groups that would decode
|
||||
* to 52 bytes max. The length byte 'A'-'Z' corresponds
|
||||
* to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
|
||||
* The end of binary is signaled with an empty line.
|
||||
*/
|
||||
int llen, used;
|
||||
struct fragment *fragment;
|
||||
unsigned long size = *sz_p;
|
||||
char *buffer = *buf_p;
|
||||
int patch_method;
|
||||
unsigned long origlen;
|
||||
char *data = NULL;
|
||||
int hunk_size = 0;
|
||||
struct fragment *frag;
|
||||
|
||||
patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
|
||||
|
||||
/* Grab the type of patch */
|
||||
llen = linelen(buffer, size);
|
||||
used = llen;
|
||||
linenr++;
|
||||
|
||||
*status_p = 0;
|
||||
|
||||
if (!strncmp(buffer, "delta ", 6)) {
|
||||
patch->is_binary = BINARY_DELTA_DEFLATED;
|
||||
patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
|
||||
patch_method = BINARY_DELTA_DEFLATED;
|
||||
origlen = strtoul(buffer + 6, NULL, 10);
|
||||
}
|
||||
else if (!strncmp(buffer, "literal ", 8)) {
|
||||
patch->is_binary = BINARY_LITERAL_DEFLATED;
|
||||
patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
|
||||
patch_method = BINARY_LITERAL_DEFLATED;
|
||||
origlen = strtoul(buffer + 8, NULL, 10);
|
||||
}
|
||||
else
|
||||
return error("unrecognized binary patch at line %d: %.*s",
|
||||
linenr-1, llen-1, buffer);
|
||||
return NULL;
|
||||
|
||||
linenr++;
|
||||
buffer += llen;
|
||||
while (1) {
|
||||
int byte_length, max_byte_length, newsize;
|
||||
@ -1044,21 +1085,79 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
|
||||
if (max_byte_length < byte_length ||
|
||||
byte_length <= max_byte_length - 4)
|
||||
goto corrupt;
|
||||
newsize = fragment->size + byte_length;
|
||||
newsize = hunk_size + byte_length;
|
||||
data = xrealloc(data, newsize);
|
||||
if (decode_85(data + fragment->size,
|
||||
buffer + 1,
|
||||
byte_length))
|
||||
if (decode_85(data + hunk_size, buffer + 1, byte_length))
|
||||
goto corrupt;
|
||||
fragment->size = newsize;
|
||||
hunk_size = newsize;
|
||||
buffer += llen;
|
||||
size -= llen;
|
||||
}
|
||||
fragment->patch = data;
|
||||
return used;
|
||||
|
||||
frag = xcalloc(1, sizeof(*frag));
|
||||
frag->patch = inflate_it(data, hunk_size, origlen);
|
||||
if (!frag->patch)
|
||||
goto corrupt;
|
||||
free(data);
|
||||
frag->size = origlen;
|
||||
*buf_p = buffer;
|
||||
*sz_p = size;
|
||||
*used_p = used;
|
||||
frag->binary_patch_method = patch_method;
|
||||
return frag;
|
||||
|
||||
corrupt:
|
||||
return error("corrupt binary patch at line %d: %.*s",
|
||||
if (data)
|
||||
free(data);
|
||||
*status_p = -1;
|
||||
error("corrupt binary patch at line %d: %.*s",
|
||||
linenr-1, llen-1, buffer);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
|
||||
{
|
||||
/* We have read "GIT binary patch\n"; what follows is a line
|
||||
* that says the patch method (currently, either "literal" or
|
||||
* "delta") and the length of data before deflating; a
|
||||
* sequence of 'length-byte' followed by base-85 encoded data
|
||||
* follows.
|
||||
*
|
||||
* When a binary patch is reversible, there is another binary
|
||||
* hunk in the same format, starting with patch method (either
|
||||
* "literal" or "delta") with the length of data, and a sequence
|
||||
* of length-byte + base-85 encoded data, terminated with another
|
||||
* empty line. This data, when applied to the postimage, produces
|
||||
* the preimage.
|
||||
*/
|
||||
struct fragment *forward;
|
||||
struct fragment *reverse;
|
||||
int status;
|
||||
int used, used_1;
|
||||
|
||||
forward = parse_binary_hunk(&buffer, &size, &status, &used);
|
||||
if (!forward && !status)
|
||||
/* there has to be one hunk (forward hunk) */
|
||||
return error("unrecognized binary patch at line %d", linenr-1);
|
||||
if (status)
|
||||
/* otherwise we already gave an error message */
|
||||
return status;
|
||||
|
||||
reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
|
||||
if (reverse)
|
||||
used += used_1;
|
||||
else if (status) {
|
||||
/* not having reverse hunk is not an error, but having
|
||||
* a corrupt reverse hunk is.
|
||||
*/
|
||||
free((void*) forward->patch);
|
||||
free(forward);
|
||||
return status;
|
||||
}
|
||||
forward->next = reverse;
|
||||
patch->fragments = forward;
|
||||
patch->is_binary = 1;
|
||||
return used;
|
||||
}
|
||||
|
||||
static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
|
||||
@ -1505,28 +1604,6 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, i
|
||||
return offset;
|
||||
}
|
||||
|
||||
static char *inflate_it(const void *data, unsigned long size,
|
||||
unsigned long inflated_size)
|
||||
{
|
||||
z_stream stream;
|
||||
void *out;
|
||||
int st;
|
||||
|
||||
memset(&stream, 0, sizeof(stream));
|
||||
|
||||
stream.next_in = (unsigned char *)data;
|
||||
stream.avail_in = size;
|
||||
stream.next_out = out = xmalloc(inflated_size);
|
||||
stream.avail_out = inflated_size;
|
||||
inflateInit(&stream);
|
||||
st = inflate(&stream, Z_FINISH);
|
||||
if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
|
||||
free(out);
|
||||
return NULL;
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
||||
static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
|
||||
{
|
||||
unsigned long dst_size;
|
||||
@ -1534,30 +1611,29 @@ static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
|
||||
void *data;
|
||||
void *result;
|
||||
|
||||
/* Binary patch is irreversible */
|
||||
if (apply_in_reverse)
|
||||
return error("cannot reverse-apply a binary patch to '%s'",
|
||||
/* Binary patch is irreversible without the optional second hunk */
|
||||
if (apply_in_reverse) {
|
||||
if (!fragment->next)
|
||||
return error("cannot reverse-apply a binary patch "
|
||||
"without the reverse hunk to '%s'",
|
||||
patch->new_name
|
||||
? patch->new_name : patch->old_name);
|
||||
|
||||
data = inflate_it(fragment->patch, fragment->size,
|
||||
patch->deflate_origlen);
|
||||
if (!data)
|
||||
return error("corrupt patch data");
|
||||
switch (patch->is_binary) {
|
||||
fragment = fragment;
|
||||
}
|
||||
data = (void*) fragment->patch;
|
||||
switch (fragment->binary_patch_method) {
|
||||
case BINARY_DELTA_DEFLATED:
|
||||
result = patch_delta(desc->buffer, desc->size,
|
||||
data,
|
||||
patch->deflate_origlen,
|
||||
fragment->size,
|
||||
&dst_size);
|
||||
free(desc->buffer);
|
||||
desc->buffer = result;
|
||||
free(data);
|
||||
break;
|
||||
case BINARY_LITERAL_DEFLATED:
|
||||
free(desc->buffer);
|
||||
desc->buffer = data;
|
||||
dst_size = patch->deflate_origlen;
|
||||
dst_size = fragment->size;
|
||||
break;
|
||||
}
|
||||
if (!desc->buffer)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user