git/resolve-undo.c
Nguyễn Thái Ngọc Duy 9c5e6c802c Convert "struct cache_entry *" to "const ..." wherever possible
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is

 - diff-lib.c: setting CE_UPTODATE

 - name-hash.c: setting CE_HASHED

 - preload-index.c, read-cache.c, unpack-trees.c and
   builtin/update-index: obvious

 - entry.c: write_entry() may refresh the checked out entry via
   fill_stat_cache_info(). This causes "non-const struct cache_entry
   *" in builtin/apply.c, builtin/checkout-index.c and
   builtin/checkout.c

 - builtin/ls-files.c: --with-tree changes stagemask and may set
   CE_UPDATE

Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.

So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.

The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:

    diff --git a/cache.h b/cache.h
    index 430d021..1692891 100644
    --- a/cache.h
    +++ b/cache.h
    @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
     #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

     struct index_state {
    -	struct cache_entry **cache;
    +	const struct cache_entry **cache;
     	unsigned int version;
     	unsigned int cache_nr, cache_alloc, cache_changed;
     	struct string_list *resolve_undo;

will help quickly identify them without bogus warnings.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-09 09:12:48 -07:00

190 lines
4.3 KiB
C

#include "cache.h"
#include "dir.h"
#include "resolve-undo.h"
#include "string-list.h"
/* The only error case is to run out of memory in string-list */
void record_resolve_undo(struct index_state *istate, struct cache_entry *ce)
{
struct string_list_item *lost;
struct resolve_undo_info *ui;
struct string_list *resolve_undo;
int stage = ce_stage(ce);
if (!stage)
return;
if (!istate->resolve_undo) {
resolve_undo = xcalloc(1, sizeof(*resolve_undo));
resolve_undo->strdup_strings = 1;
istate->resolve_undo = resolve_undo;
}
resolve_undo = istate->resolve_undo;
lost = string_list_insert(resolve_undo, ce->name);
if (!lost->util)
lost->util = xcalloc(1, sizeof(*ui));
ui = lost->util;
hashcpy(ui->sha1[stage - 1], ce->sha1);
ui->mode[stage - 1] = ce->ce_mode;
}
void resolve_undo_write(struct strbuf *sb, struct string_list *resolve_undo)
{
struct string_list_item *item;
for_each_string_list_item(item, resolve_undo) {
struct resolve_undo_info *ui = item->util;
int i;
if (!ui)
continue;
strbuf_addstr(sb, item->string);
strbuf_addch(sb, 0);
for (i = 0; i < 3; i++)
strbuf_addf(sb, "%o%c", ui->mode[i], 0);
for (i = 0; i < 3; i++) {
if (!ui->mode[i])
continue;
strbuf_add(sb, ui->sha1[i], 20);
}
}
}
struct string_list *resolve_undo_read(const char *data, unsigned long size)
{
struct string_list *resolve_undo;
size_t len;
char *endptr;
int i;
resolve_undo = xcalloc(1, sizeof(*resolve_undo));
resolve_undo->strdup_strings = 1;
while (size) {
struct string_list_item *lost;
struct resolve_undo_info *ui;
len = strlen(data) + 1;
if (size <= len)
goto error;
lost = string_list_insert(resolve_undo, data);
if (!lost->util)
lost->util = xcalloc(1, sizeof(*ui));
ui = lost->util;
size -= len;
data += len;
for (i = 0; i < 3; i++) {
ui->mode[i] = strtoul(data, &endptr, 8);
if (!endptr || endptr == data || *endptr)
goto error;
len = (endptr + 1) - (char*)data;
if (size <= len)
goto error;
size -= len;
data += len;
}
for (i = 0; i < 3; i++) {
if (!ui->mode[i])
continue;
if (size < 20)
goto error;
hashcpy(ui->sha1[i], (const unsigned char *)data);
size -= 20;
data += 20;
}
}
return resolve_undo;
error:
string_list_clear(resolve_undo, 1);
error("Index records invalid resolve-undo information");
return NULL;
}
void resolve_undo_clear_index(struct index_state *istate)
{
struct string_list *resolve_undo = istate->resolve_undo;
if (!resolve_undo)
return;
string_list_clear(resolve_undo, 1);
free(resolve_undo);
istate->resolve_undo = NULL;
istate->cache_changed = 1;
}
int unmerge_index_entry_at(struct index_state *istate, int pos)
{
const struct cache_entry *ce;
struct string_list_item *item;
struct resolve_undo_info *ru;
int i, err = 0, matched;
if (!istate->resolve_undo)
return pos;
ce = istate->cache[pos];
if (ce_stage(ce)) {
/* already unmerged */
while ((pos < istate->cache_nr) &&
! strcmp(istate->cache[pos]->name, ce->name))
pos++;
return pos - 1; /* return the last entry processed */
}
item = string_list_lookup(istate->resolve_undo, ce->name);
if (!item)
return pos;
ru = item->util;
if (!ru)
return pos;
matched = ce->ce_flags & CE_MATCHED;
remove_index_entry_at(istate, pos);
for (i = 0; i < 3; i++) {
struct cache_entry *nce;
if (!ru->mode[i])
continue;
nce = make_cache_entry(ru->mode[i], ru->sha1[i],
ce->name, i + 1, 0);
if (matched)
nce->ce_flags |= CE_MATCHED;
if (add_index_entry(istate, nce, ADD_CACHE_OK_TO_ADD)) {
err = 1;
error("cannot unmerge '%s'", ce->name);
}
}
if (err)
return pos;
free(ru);
item->util = NULL;
return unmerge_index_entry_at(istate, pos);
}
void unmerge_marked_index(struct index_state *istate)
{
int i;
if (!istate->resolve_undo)
return;
for (i = 0; i < istate->cache_nr; i++) {
const struct cache_entry *ce = istate->cache[i];
if (ce->ce_flags & CE_MATCHED)
i = unmerge_index_entry_at(istate, i);
}
}
void unmerge_index(struct index_state *istate, const char **pathspec)
{
int i;
if (!istate->resolve_undo)
return;
for (i = 0; i < istate->cache_nr; i++) {
const struct cache_entry *ce = istate->cache[i];
if (!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL))
continue;
i = unmerge_index_entry_at(istate, i);
}
}