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git-apply: parse the whole list of patches into memory first

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Make it a clear two-phase thing: first a read-only parse of
the patch itself (which is independent of any current index
information), and then the second phase actually uses the patch.

The second phase might not be a real apply, it could be just a
diffstat, for example. Which is trivial to do once the patch is
parsed.
This commit is contained in:
Linus Torvalds 2005-05-26 10:23:51 -07:00
parent 368da62598
commit 19c58fb84d
1 changed files with 146 additions and 90 deletions
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226
apply.c
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@ -27,9 +27,23 @@ static const char apply_usage[] = "git-apply <patch>";
* things are flags, where -1 means "don't know yet". * things are flags, where -1 means "don't know yet".
*/ */
static int linenr = 1; static int linenr = 1;
static int old_mode, new_mode; static char *def_name = NULL;
static char *old_name, *new_name, *def_name;
static int is_rename, is_copy, is_new, is_delete; struct fragment {
unsigned long oldpos, oldlines;
unsigned long newpos, newlines;
const char *patch;
int size;
struct fragment *next;
};
struct patch {
char *new_name, *old_name;
unsigned int old_mode, new_mode;
int is_rename, is_copy, is_new, is_delete;
struct fragment *fragments;
struct patch *next;
};
#define CHUNKSIZE (8192) #define CHUNKSIZE (8192)
#define SLOP (16) #define SLOP (16)
@ -159,7 +173,7 @@ static char * find_name(const char *line, char *def, int p_value, int terminate)
* files, we can happily check the index for a match, but for creating a * files, we can happily check the index for a match, but for creating a
* new file we should try to match whatever "patch" does. I have no idea. * new file we should try to match whatever "patch" does. I have no idea.
*/ */
static void parse_traditional_patch(const char *first, const char *second) static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
{ {
int p_value = 1; int p_value = 1;
char *name; char *name;
@ -167,23 +181,25 @@ static void parse_traditional_patch(const char *first, const char *second)
first += 4; // skip "--- " first += 4; // skip "--- "
second += 4; // skip "+++ " second += 4; // skip "+++ "
if (is_dev_null(first)) { if (is_dev_null(first)) {
is_new = 1; patch->is_new = 1;
patch->is_delete = 0;
name = find_name(second, def_name, p_value, TERM_SPACE | TERM_TAB); name = find_name(second, def_name, p_value, TERM_SPACE | TERM_TAB);
new_name = name; patch->new_name = name;
} else if (is_dev_null(second)) { } else if (is_dev_null(second)) {
is_delete = 1; patch->is_new = 0;
patch->is_delete = 1;
name = find_name(first, def_name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB); name = find_name(first, def_name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
old_name = name; patch->old_name = name;
} else { } else {
name = find_name(first, def_name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB); name = find_name(first, def_name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
name = find_name(second, name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB); name = find_name(second, name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
old_name = new_name = name; patch->old_name = patch->new_name = name;
} }
if (!name) if (!name)
die("unable to find filename in patch at line %d", linenr); die("unable to find filename in patch at line %d", linenr);
} }
static int gitdiff_hdrend(const char *line) static int gitdiff_hdrend(const char *line, struct patch *patch)
{ {
return -1; return -1;
} }
@ -232,71 +248,71 @@ absolute_path:
return NULL; return NULL;
} }
static int gitdiff_oldname(const char *line) static int gitdiff_oldname(const char *line, struct patch *patch)
{ {
old_name = gitdiff_verify_name(line, is_new, old_name, "old"); patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
return 0; return 0;
} }
static int gitdiff_newname(const char *line) static int gitdiff_newname(const char *line, struct patch *patch)
{ {
new_name = gitdiff_verify_name(line, is_delete, new_name, "new"); patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
return 0; return 0;
} }
static int gitdiff_oldmode(const char *line) static int gitdiff_oldmode(const char *line, struct patch *patch)
{ {
old_mode = strtoul(line, NULL, 8); patch->old_mode = strtoul(line, NULL, 8);
return 0; return 0;
} }
static int gitdiff_newmode(const char *line) static int gitdiff_newmode(const char *line, struct patch *patch)
{ {
new_mode = strtoul(line, NULL, 8); patch->new_mode = strtoul(line, NULL, 8);
return 0; return 0;
} }
static int gitdiff_delete(const char *line) static int gitdiff_delete(const char *line, struct patch *patch)
{ {
is_delete = 1; patch->is_delete = 1;
return gitdiff_oldmode(line); return gitdiff_oldmode(line, patch);
} }
static int gitdiff_newfile(const char *line) static int gitdiff_newfile(const char *line, struct patch *patch)
{ {
is_new = 1; patch->is_new = 1;
return gitdiff_newmode(line); return gitdiff_newmode(line, patch);
} }
static int gitdiff_copysrc(const char *line) static int gitdiff_copysrc(const char *line, struct patch *patch)
{ {
is_copy = 1; patch->is_copy = 1;
old_name = find_name(line, NULL, 0, 0); patch->old_name = find_name(line, NULL, 0, 0);
return 0; return 0;
} }
static int gitdiff_copydst(const char *line) static int gitdiff_copydst(const char *line, struct patch *patch)
{ {
is_copy = 1; patch->is_copy = 1;
new_name = find_name(line, NULL, 0, 0); patch->new_name = find_name(line, NULL, 0, 0);
return 0; return 0;
} }
static int gitdiff_renamesrc(const char *line) static int gitdiff_renamesrc(const char *line, struct patch *patch)
{ {
is_rename = 1; patch->is_rename = 1;
old_name = find_name(line, NULL, 0, 0); patch->old_name = find_name(line, NULL, 0, 0);
return 0; return 0;
} }
static int gitdiff_renamedst(const char *line) static int gitdiff_renamedst(const char *line, struct patch *patch)
{ {
is_rename = 1; patch->is_rename = 1;
new_name = find_name(line, NULL, 0, 0); patch->new_name = find_name(line, NULL, 0, 0);
return 0; return 0;
} }
static int gitdiff_similarity(const char *line) static int gitdiff_similarity(const char *line, struct patch *patch)
{ {
return 0; return 0;
} }
@ -305,19 +321,19 @@ static int gitdiff_similarity(const char *line)
* This is normal for a diff that doesn't change anything: we'll fall through * This is normal for a diff that doesn't change anything: we'll fall through
* into the next diff. Tell the parser to break out. * into the next diff. Tell the parser to break out.
*/ */
static int gitdiff_unrecognized(const char *line) static int gitdiff_unrecognized(const char *line, struct patch *patch)
{ {
return -1; return -1;
} }
/* Verify that we recognize the lines following a git header */ /* Verify that we recognize the lines following a git header */
static int parse_git_header(char *line, int len, unsigned int size) static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
{ {
unsigned long offset; unsigned long offset;
/* A git diff has explicit new/delete information, so we don't guess */ /* A git diff has explicit new/delete information, so we don't guess */
is_new = 0; patch->is_new = 0;
is_delete = 0; patch->is_delete = 0;
line += len; line += len;
size -= len; size -= len;
@ -325,7 +341,7 @@ static int parse_git_header(char *line, int len, unsigned int size)
for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) { for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
static const struct opentry { static const struct opentry {
const char *str; const char *str;
int (*fn)(const char *); int (*fn)(const char *, struct patch *);
} optable[] = { } optable[] = {
{ "@@ -", gitdiff_hdrend }, { "@@ -", gitdiff_hdrend },
{ "--- ", gitdiff_oldname }, { "--- ", gitdiff_oldname },
@ -351,7 +367,7 @@ static int parse_git_header(char *line, int len, unsigned int size)
int oplen = strlen(p->str); int oplen = strlen(p->str);
if (len < oplen || memcmp(p->str, line, oplen)) if (len < oplen || memcmp(p->str, line, oplen))
continue; continue;
if (p->fn(line + oplen) < 0) if (p->fn(line + oplen, patch) < 0)
return offset; return offset;
break; break;
} }
@ -393,7 +409,7 @@ static int parse_num(const char *line, int len, int offset, const char *expect,
* Parse a unified diff fragment header of the * Parse a unified diff fragment header of the
* form "@@ -a,b +c,d @@" * form "@@ -a,b +c,d @@"
*/ */
static int parse_fragment_header(char *line, int len, unsigned long *pos) static int parse_fragment_header(char *line, int len, struct fragment *fragment)
{ {
int offset; int offset;
@ -401,22 +417,22 @@ static int parse_fragment_header(char *line, int len, unsigned long *pos)
return -1; return -1;
/* Figure out the number of lines in a fragment */ /* Figure out the number of lines in a fragment */
offset = parse_num(line, len, 4, ",", pos); offset = parse_num(line, len, 4, ",", &fragment->oldpos);
offset = parse_num(line, len, offset, " +", pos+1); offset = parse_num(line, len, offset, " +", &fragment->oldlines);
offset = parse_num(line, len, offset, ",", pos+2); offset = parse_num(line, len, offset, ",", &fragment->newpos);
offset = parse_num(line, len, offset, " @@", pos+3); offset = parse_num(line, len, offset, " @@", &fragment->newlines);
return offset; return offset;
} }
static int find_header(char *line, unsigned long size, int *hdrsize) static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
{ {
unsigned long offset, len; unsigned long offset, len;
is_rename = is_copy = 0; patch->is_rename = patch->is_copy = 0;
is_new = is_delete = -1; patch->is_new = patch->is_delete = -1;
old_mode = new_mode = 0; patch->old_mode = patch->new_mode = 0;
def_name = old_name = new_name = NULL; patch->old_name = patch->new_name = NULL;
for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) { for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
unsigned long nextlen; unsigned long nextlen;
@ -434,8 +450,8 @@ static int find_header(char *line, unsigned long size, int *hdrsize)
* patch has become corrupted/broken up. * patch has become corrupted/broken up.
*/ */
if (!memcmp("@@ -", line, 4)) { if (!memcmp("@@ -", line, 4)) {
unsigned long pos[4]; struct fragment dummy;
if (parse_fragment_header(line, len, pos) < 0) if (parse_fragment_header(line, len, &dummy) < 0)
continue; continue;
error("patch fragment without header at line %d: %.*s", linenr, len-1, line); error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
} }
@ -448,7 +464,7 @@ static int find_header(char *line, unsigned long size, int *hdrsize)
* or mode change, so we handle that specially * or mode change, so we handle that specially
*/ */
if (!memcmp("diff --git ", line, 11)) { if (!memcmp("diff --git ", line, 11)) {
int git_hdr_len = parse_git_header(line, len, size); int git_hdr_len = parse_git_header(line, len, size, patch);
if (git_hdr_len < 0) if (git_hdr_len < 0)
continue; continue;
@ -470,7 +486,7 @@ static int find_header(char *line, unsigned long size, int *hdrsize)
continue; continue;
/* Ok, we'll consider it a patch */ /* Ok, we'll consider it a patch */
parse_traditional_patch(line, line+len); parse_traditional_patch(line, line+len, patch);
*hdrsize = len + nextlen; *hdrsize = len + nextlen;
linenr += 2; linenr += 2;
return offset; return offset;
@ -485,21 +501,21 @@ static int find_header(char *line, unsigned long size, int *hdrsize)
* part of a patch, and a "---" that starts the next * part of a patch, and a "---" that starts the next
* patch is to look at the line counts.. * patch is to look at the line counts..
*/ */
static int apply_fragment(char *line, unsigned long size) static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
{ {
int len = linelen(line, size), offset; int len = linelen(line, size), offset;
unsigned long pos[4], oldlines, newlines; unsigned long pos[4], oldlines, newlines;
offset = parse_fragment_header(line, len, pos); offset = parse_fragment_header(line, len, fragment);
if (offset < 0) if (offset < 0)
return -1; return -1;
oldlines = pos[1]; oldlines = fragment->oldlines;
newlines = pos[3]; newlines = fragment->newlines;
if (is_new < 0 && (pos[0] || oldlines)) if (patch->is_new < 0 && (pos[0] || oldlines))
is_new = 0; patch->is_new = 0;
if (is_delete < 0 && (pos[1] || newlines)) if (patch->is_delete < 0 && (pos[1] || newlines))
is_delete = 0; patch->is_delete = 0;
/* Parse the thing.. */ /* Parse the thing.. */
line += len; line += len;
@ -529,16 +545,26 @@ static int apply_fragment(char *line, unsigned long size)
return offset; return offset;
} }
static int apply_single_patch(char *line, unsigned long size) static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
{ {
unsigned long offset = 0; unsigned long offset = 0;
struct fragment **fragp = &patch->fragments;
while (size > 4 && !memcmp(line, "@@ -", 4)) { while (size > 4 && !memcmp(line, "@@ -", 4)) {
int len = apply_fragment(line, size); struct fragment *fragment;
int len;
fragment = xmalloc(sizeof(*fragment));
memset(fragment, 0, sizeof(*fragment));
len = parse_fragment(line, size, patch, fragment);
if (len <= 0) if (len <= 0)
die("corrupt patch at line %d", linenr); die("corrupt patch at line %d", linenr);
printf("applying fragment:\n%.*s\n\n", len, line); fragment->patch = line;
fragment->size = len;
*fragp = fragment;
fragp = &fragment->next;
offset += len; offset += len;
line += len; line += len;
@ -547,52 +573,82 @@ printf("applying fragment:\n%.*s\n\n", len, line);
return offset; return offset;
} }
static int apply_chunk(char *buffer, unsigned long size) static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
{ {
int hdrsize, patchsize; int hdrsize, patchsize;
int offset = find_header(buffer, size, &hdrsize); int offset = find_header(buffer, size, &hdrsize, patch);
char *header, *patch;
if (offset < 0) if (offset < 0)
return offset; return offset;
header = buffer + offset;
printf("Found header:\n%.*s\n\n", hdrsize, header); patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
printf("Rename: %d\n", is_rename);
printf("Copy: %d\n", is_copy);
printf("New: %d\n", is_new);
printf("Delete: %d\n", is_delete);
printf("Mode: %o:%o\n", old_mode, new_mode);
printf("Name: '%s':'%s'\n", old_name, new_name);
if (old_name && cache_name_pos(old_name, strlen(old_name)) < 0) return offset + hdrsize + patchsize;
}
static void apply_patch_list(struct patch *patch)
{
if (!patch)
die("no patch found");
do {
const char *old_name = patch->old_name;
const char *new_name = patch->new_name;
struct fragment *frag;
if (old_name) {
if (cache_name_pos(old_name, strlen(old_name)) < 0)
die("file %s does not exist", old_name); die("file %s does not exist", old_name);
if (new_name && (is_new | is_rename | is_copy)) { if (patch->is_new < 0)
patch->is_new = 0;
}
if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
if (cache_name_pos(new_name, strlen(new_name)) >= 0) if (cache_name_pos(new_name, strlen(new_name)) >= 0)
die("file %s already exists", new_name); die("file %s already exists", new_name);
} }
patch = header + hdrsize; printf("Applying patch to %s\n", new_name);
patchsize = apply_single_patch(patch, size - offset - hdrsize); printf(" new=%d delete=%d copy=%d rename=%d\n",
patch->is_new, patch->is_delete, patch->is_copy, patch->is_rename);
if (patch->old_mode != patch->new_mode)
printf(" %o->%o\n", patch->old_mode, patch->new_mode);
frag = patch->fragments;
while (frag) {
printf("Fragment %lu,%lu -> %lu,%lu\n%.*s",
frag->oldpos, frag->oldlines,
frag->newpos, frag->newlines,
frag->size, frag->patch);
frag = frag->next;
}
return offset + hdrsize + patchsize; } while ((patch = patch->next) != NULL);
} }
static int apply_patch(int fd) static int apply_patch(int fd)
{ {
unsigned long offset, size; unsigned long offset, size;
char *buffer = read_patch_file(fd, &size); char *buffer = read_patch_file(fd, &size);
struct patch *list = NULL, **listp = &list;
if (!buffer) if (!buffer)
return -1; return -1;
offset = 0; offset = 0;
while (size > 0) { while (size > 0) {
int nr = apply_chunk(buffer + offset, size); struct patch *patch;
int nr;
patch = xmalloc(sizeof(*patch));
memset(patch, 0, sizeof(*patch));
nr = parse_chunk(buffer + offset, size, patch);
if (nr < 0) if (nr < 0)
break; break;
*listp = patch;
listp = &patch->next;
offset += nr; offset += nr;
size -= nr; size -= nr;
} }
apply_patch_list(list);
free(buffer); free(buffer);
return 0; return 0;
} }