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git/builtin-rerere.c
Andy Whitcroft 93822c2239 short i/o: fix calls to write to use xwrite or write_in_full 
We have a number of badly checked write() calls.  Often we are
expecting write() to write exactly the size we requested or fail,
this fails to handle interrupts or short writes.  Switch to using
the new write_in_full().  Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xwrite().

Note, the changes to config handling are much larger and handled
in the next patch in the sequence.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 15:44:47 -08:00

422 lines
10 KiB
C
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#include "cache.h"
#include "path-list.h"
#include "xdiff/xdiff.h"
#include "xdiff-interface.h"
#include <time.h>
static const char git_rerere_usage[] =
"git-rerere [clear | status | diff | gc]";
/* these values are days */
static int cutoff_noresolve = 15;
static int cutoff_resolve = 60;
static char *merge_rr_path;
static const char *rr_path(const char *name, const char *file)
{
return git_path("rr-cache/%s/%s", name, file);
}
static void read_rr(struct path_list *rr)
{
unsigned char sha1[20];
char buf[PATH_MAX];
FILE *in = fopen(merge_rr_path, "r");
if (!in)
return;
while (fread(buf, 40, 1, in) == 1) {
int i;
char *name;
if (get_sha1_hex(buf, sha1))
die("corrupt MERGE_RR");
buf[40] = '\0';
name = xstrdup(buf);
if (fgetc(in) != '\t')
die("corrupt MERGE_RR");
for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
; /* do nothing */
if (i == sizeof(buf))
die("filename too long");
path_list_insert(buf, rr)->util = xstrdup(name);
}
fclose(in);
}
static struct lock_file write_lock;
static int write_rr(struct path_list *rr, int out_fd)
{
int i;
for (i = 0; i < rr->nr; i++) {
const char *path = rr->items[i].path;
int length = strlen(path) + 1;
if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
write_in_full(out_fd, "\t", 1) != 1 ||
write_in_full(out_fd, path, length) != length)
die("unable to write rerere record");
}
close(out_fd);
return commit_lock_file(&write_lock);
}
struct buffer {
char *ptr;
int nr, alloc;
};
static void append_line(struct buffer *buffer, const char *line)
{
int len = strlen(line);
if (buffer->nr + len > buffer->alloc) {
buffer->alloc = alloc_nr(buffer->nr + len);
buffer->ptr = xrealloc(buffer->ptr, buffer->alloc);
}
memcpy(buffer->ptr + buffer->nr, line, len);
buffer->nr += len;
}
static int handle_file(const char *path,
unsigned char *sha1, const char *output)
{
SHA_CTX ctx;
char buf[1024];
int hunk = 0, hunk_no = 0;
struct buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
struct buffer *one = &minus, *two = &plus;
FILE *f = fopen(path, "r");
FILE *out;
if (!f)
return error("Could not open %s", path);
if (output) {
out = fopen(output, "w");
if (!out) {
fclose(f);
return error("Could not write %s", output);
}
} else
out = NULL;
if (sha1)
SHA1_Init(&ctx);
while (fgets(buf, sizeof(buf), f)) {
if (!strncmp("<<<<<<< ", buf, 8))
hunk = 1;
else if (!strncmp("=======", buf, 7))
hunk = 2;
else if (!strncmp(">>>>>>> ", buf, 8)) {
hunk_no++;
hunk = 0;
if (memcmp(one->ptr, two->ptr, one->nr < two->nr ?
one->nr : two->nr) > 0) {
struct buffer *swap = one;
one = two;
two = swap;
}
if (out) {
fputs("<<<<<<<\n", out);
fwrite(one->ptr, one->nr, 1, out);
fputs("=======\n", out);
fwrite(two->ptr, two->nr, 1, out);
fputs(">>>>>>>\n", out);
}
if (sha1) {
SHA1_Update(&ctx, one->ptr, one->nr);
SHA1_Update(&ctx, "\0", 1);
SHA1_Update(&ctx, two->ptr, two->nr);
SHA1_Update(&ctx, "\0", 1);
}
} else if (hunk == 1)
append_line(one, buf);
else if (hunk == 2)
append_line(two, buf);
else if (out)
fputs(buf, out);
}
fclose(f);
if (out)
fclose(out);
if (sha1)
SHA1_Final(sha1, &ctx);
return hunk_no;
}
static int find_conflict(struct path_list *conflict)
{
int i;
if (read_cache() < 0)
return error("Could not read index");
for (i = 0; i + 2 < active_nr; i++) {
struct cache_entry *e1 = active_cache[i];
struct cache_entry *e2 = active_cache[i + 1];
struct cache_entry *e3 = active_cache[i + 2];
if (ce_stage(e1) == 1 && ce_stage(e2) == 2 &&
ce_stage(e3) == 3 && ce_same_name(e1, e2) &&
ce_same_name(e1, e3)) {
path_list_insert((const char *)e1->name, conflict);
i += 3;
}
}
return 0;
}
static int merge(const char *name, const char *path)
{
int ret;
mmfile_t cur, base, other;
mmbuffer_t result = {NULL, 0};
xpparam_t xpp = {XDF_NEED_MINIMAL};
if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
return 1;
if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
read_mmfile(&base, rr_path(name, "preimage")) ||
read_mmfile(&other, rr_path(name, "postimage")))
return 1;
ret = xdl_merge(&base, &cur, "", &other, "",
&xpp, XDL_MERGE_ZEALOUS, &result);
if (!ret) {
FILE *f = fopen(path, "w");
if (!f)
return error("Could not write to %s", path);
fwrite(result.ptr, result.size, 1, f);
fclose(f);
}
free(cur.ptr);
free(base.ptr);
free(other.ptr);
free(result.ptr);
return ret;
}
static void unlink_rr_item(const char *name)
{
unlink(rr_path(name, "thisimage"));
unlink(rr_path(name, "preimage"));
unlink(rr_path(name, "postimage"));
rmdir(git_path("rr-cache/%s", name));
}
static void garbage_collect(struct path_list *rr)
{
struct path_list to_remove = { NULL, 0, 0, 1 };
char buf[1024];
DIR *dir;
struct dirent *e;
int len, i, cutoff;
time_t now = time(NULL), then;
strlcpy(buf, git_path("rr-cache"), sizeof(buf));
len = strlen(buf);
dir = opendir(buf);
strcpy(buf + len++, "/");
while ((e = readdir(dir))) {
const char *name = e->d_name;
struct stat st;
if (name[0] == '.' && (name[1] == '\0' ||
(name[1] == '.' && name[2] == '\0')))
continue;
i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
if (stat(buf, &st))
continue;
then = st.st_mtime;
strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
if (then < now - cutoff * 86400) {
buf[len + i] = '\0';
path_list_insert(xstrdup(name), &to_remove);
}
}
for (i = 0; i < to_remove.nr; i++)
unlink_rr_item(to_remove.items[i].path);
path_list_clear(&to_remove, 0);
}
static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
{
int i;
for (i = 0; i < nbuf; i++)
if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
return -1;
return 0;
}
static int diff_two(const char *file1, const char *label1,
const char *file2, const char *label2)
{
xpparam_t xpp;
xdemitconf_t xecfg;
xdemitcb_t ecb;
mmfile_t minus, plus;
if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
return 1;
printf("--- a/%s\n+++ b/%s\n", label1, label2);
fflush(stdout);
xpp.flags = XDF_NEED_MINIMAL;
xecfg.ctxlen = 3;
xecfg.flags = 0;
ecb.outf = outf;
xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
free(minus.ptr);
free(plus.ptr);
return 0;
}
static int copy_file(const char *src, const char *dest)
{
FILE *in, *out;
char buffer[32768];
int count;
if (!(in = fopen(src, "r")))
return error("Could not open %s", src);
if (!(out = fopen(dest, "w")))
return error("Could not open %s", dest);
while ((count = fread(buffer, 1, sizeof(buffer), in)))
fwrite(buffer, 1, count, out);
fclose(in);
fclose(out);
return 0;
}
static int do_plain_rerere(struct path_list *rr, int fd)
{
struct path_list conflict = { NULL, 0, 0, 1 };
int i;
find_conflict(&conflict);
/*
* MERGE_RR records paths with conflicts immediately after merge
* failed. Some of the conflicted paths might have been hand resolved
* in the working tree since then, but the initial run would catch all
* and register their preimages.
*/
for (i = 0; i < conflict.nr; i++) {
const char *path = conflict.items[i].path;
if (!path_list_has_path(rr, path)) {
unsigned char sha1[20];
char *hex;
int ret;
ret = handle_file(path, sha1, NULL);
if (ret < 1)
continue;
hex = xstrdup(sha1_to_hex(sha1));
path_list_insert(path, rr)->util = hex;
if (mkdir(git_path("rr-cache/%s", hex), 0755))
continue;;
handle_file(path, NULL, rr_path(hex, "preimage"));
fprintf(stderr, "Recorded preimage for '%s'\n", path);
}
}
/*
* Now some of the paths that had conflicts earlier might have been
* hand resolved. Others may be similar to a conflict already that
* was resolved before.
*/
for (i = 0; i < rr->nr; i++) {
struct stat st;
int ret;
const char *path = rr->items[i].path;
const char *name = (const char *)rr->items[i].util;
if (!stat(rr_path(name, "preimage"), &st) &&
!stat(rr_path(name, "postimage"), &st)) {
if (!merge(name, path)) {
fprintf(stderr, "Resolved '%s' using "
"previous resolution.\n", path);
goto tail_optimization;
}
}
/* Let's see if we have resolved it. */
ret = handle_file(path, NULL, NULL);
if (ret)
continue;
fprintf(stderr, "Recorded resolution for '%s'.\n", path);
copy_file(path, rr_path(name, "postimage"));
tail_optimization:
if (i < rr->nr - 1)
memmove(rr->items + i,
rr->items + i + 1,
sizeof(rr->items[0]) * (rr->nr - i - 1));
rr->nr--;
i--;
}
return write_rr(rr, fd);
}
static int git_rerere_config(const char *var, const char *value)
{
if (!strcmp(var, "gc.rerereresolved"))
cutoff_resolve = git_config_int(var, value);
else if (!strcmp(var, "gc.rerereunresolved"))
cutoff_noresolve = git_config_int(var, value);
else
return git_default_config(var, value);
return 0;
}
int cmd_rerere(int argc, const char **argv, const char *prefix)
{
struct path_list merge_rr = { NULL, 0, 0, 1 };
int i, fd = -1;
struct stat st;
if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
return 0;
git_config(git_rerere_config);
merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
read_rr(&merge_rr);
if (argc < 2)
return do_plain_rerere(&merge_rr, fd);
else if (!strcmp(argv[1], "clear")) {
for (i = 0; i < merge_rr.nr; i++) {
const char *name = (const char *)merge_rr.items[i].util;
if (!stat(git_path("rr-cache/%s", name), &st) &&
S_ISDIR(st.st_mode) &&
stat(rr_path(name, "postimage"), &st))
unlink_rr_item(name);
}
unlink(merge_rr_path);
} else if (!strcmp(argv[1], "gc"))
garbage_collect(&merge_rr);
else if (!strcmp(argv[1], "status"))
for (i = 0; i < merge_rr.nr; i++)
printf("%s\n", merge_rr.items[i].path);
else if (!strcmp(argv[1], "diff"))
for (i = 0; i < merge_rr.nr; i++) {
const char *path = merge_rr.items[i].path;
const char *name = (const char *)merge_rr.items[i].util;
diff_two(rr_path(name, "preimage"), path, path, path);
}
else
usage(git_rerere_usage);
path_list_clear(&merge_rr, 1);
return 0;
}
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