Revision 3ebbd00cf3c5a7c6f90e2fed8adaf0c5145fb4ac authored by Jim Hill on 31 May 2015, 18:16:45 UTC, committed by Junio C Hamano on 10 August 2015, 19:51:13 UTC
The loop in strbuf_read() uses xread() repeatedly while extending the strbuf until the call returns zero. If the buffer is sufficiently large to begin with, this results in xread() returning the remainder of the file to the end (returning non-zero), the loop extending the strbuf, and then making another call to xread() to have it return zero. By using read_in_full(), we can tell when the read reached the end of file: when it returns less than was requested, it's eof. This way we can avoid an extra iteration that allocates an extra 8kB that is never used. Signed-off-by: Jim Hill <gjthill@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 282616c
walker.c
#include "cache.h"
#include "walker.h"
#include "commit.h"
#include "tree.h"
#include "tree-walk.h"
#include "tag.h"
#include "blob.h"
#include "refs.h"
static unsigned char current_commit_sha1[20];
void walker_say(struct walker *walker, const char *fmt, const char *hex)
{
if (walker->get_verbosely)
fprintf(stderr, fmt, hex);
}
static void report_missing(const struct object *obj)
{
char missing_hex[41];
strcpy(missing_hex, sha1_to_hex(obj->sha1));
fprintf(stderr, "Cannot obtain needed %s %s\n",
obj->type ? typename(obj->type): "object", missing_hex);
if (!is_null_sha1(current_commit_sha1))
fprintf(stderr, "while processing commit %s.\n",
sha1_to_hex(current_commit_sha1));
}
static int process(struct walker *walker, struct object *obj);
static int process_tree(struct walker *walker, struct tree *tree)
{
struct tree_desc desc;
struct name_entry entry;
if (parse_tree(tree))
return -1;
init_tree_desc(&desc, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
struct object *obj = NULL;
/* submodule commits are not stored in the superproject */
if (S_ISGITLINK(entry.mode))
continue;
if (S_ISDIR(entry.mode)) {
struct tree *tree = lookup_tree(entry.sha1);
if (tree)
obj = &tree->object;
}
else {
struct blob *blob = lookup_blob(entry.sha1);
if (blob)
obj = &blob->object;
}
if (!obj || process(walker, obj))
return -1;
}
free_tree_buffer(tree);
return 0;
}
/* Remember to update object flag allocation in object.h */
#define COMPLETE (1U << 0)
#define SEEN (1U << 1)
#define TO_SCAN (1U << 2)
static struct commit_list *complete = NULL;
static int process_commit(struct walker *walker, struct commit *commit)
{
if (parse_commit(commit))
return -1;
while (complete && complete->item->date >= commit->date) {
pop_most_recent_commit(&complete, COMPLETE);
}
if (commit->object.flags & COMPLETE)
return 0;
hashcpy(current_commit_sha1, commit->object.sha1);
walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
if (walker->get_tree) {
if (process(walker, &commit->tree->object))
return -1;
if (!walker->get_all)
walker->get_tree = 0;
}
if (walker->get_history) {
struct commit_list *parents = commit->parents;
for (; parents; parents = parents->next) {
if (process(walker, &parents->item->object))
return -1;
}
}
return 0;
}
static int process_tag(struct walker *walker, struct tag *tag)
{
if (parse_tag(tag))
return -1;
return process(walker, tag->tagged);
}
static struct object_list *process_queue = NULL;
static struct object_list **process_queue_end = &process_queue;
static int process_object(struct walker *walker, struct object *obj)
{
if (obj->type == OBJ_COMMIT) {
if (process_commit(walker, (struct commit *)obj))
return -1;
return 0;
}
if (obj->type == OBJ_TREE) {
if (process_tree(walker, (struct tree *)obj))
return -1;
return 0;
}
if (obj->type == OBJ_BLOB) {
return 0;
}
if (obj->type == OBJ_TAG) {
if (process_tag(walker, (struct tag *)obj))
return -1;
return 0;
}
return error("Unable to determine requirements "
"of type %s for %s",
typename(obj->type), sha1_to_hex(obj->sha1));
}
static int process(struct walker *walker, struct object *obj)
{
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (has_sha1_file(obj->sha1)) {
/* We already have it, so we should scan it now. */
obj->flags |= TO_SCAN;
}
else {
if (obj->flags & COMPLETE)
return 0;
walker->prefetch(walker, obj->sha1);
}
object_list_insert(obj, process_queue_end);
process_queue_end = &(*process_queue_end)->next;
return 0;
}
static int loop(struct walker *walker)
{
struct object_list *elem;
while (process_queue) {
struct object *obj = process_queue->item;
elem = process_queue;
process_queue = elem->next;
free(elem);
if (!process_queue)
process_queue_end = &process_queue;
/* If we are not scanning this object, we placed it in
* the queue because we needed to fetch it first.
*/
if (! (obj->flags & TO_SCAN)) {
if (walker->fetch(walker, obj->sha1)) {
report_missing(obj);
return -1;
}
}
if (!obj->type)
parse_object(obj->sha1);
if (process_object(walker, obj))
return -1;
}
return 0;
}
static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
{
if (!get_sha1_hex(target, sha1))
return 0;
if (!check_refname_format(target, 0)) {
struct ref *ref = alloc_ref(target);
if (!walker->fetch_ref(walker, ref)) {
hashcpy(sha1, ref->old_sha1);
free(ref);
return 0;
}
free(ref);
}
return -1;
}
static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
struct commit *commit = lookup_commit_reference_gently(sha1, 1);
if (commit) {
commit->object.flags |= COMPLETE;
commit_list_insert_by_date(commit, &complete);
}
return 0;
}
int walker_targets_stdin(char ***target, const char ***write_ref)
{
int targets = 0, targets_alloc = 0;
struct strbuf buf = STRBUF_INIT;
*target = NULL; *write_ref = NULL;
while (1) {
char *rf_one = NULL;
char *tg_one;
if (strbuf_getline(&buf, stdin, '\n') == EOF)
break;
tg_one = buf.buf;
rf_one = strchr(tg_one, '\t');
if (rf_one)
*rf_one++ = 0;
if (targets >= targets_alloc) {
targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
*target = xrealloc(*target, targets_alloc * sizeof(**target));
*write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
}
(*target)[targets] = xstrdup(tg_one);
(*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
targets++;
}
strbuf_release(&buf);
return targets;
}
void walker_targets_free(int targets, char **target, const char **write_ref)
{
while (targets--) {
free(target[targets]);
if (write_ref)
free((char *) write_ref[targets]);
}
}
int walker_fetch(struct walker *walker, int targets, char **target,
const char **write_ref, const char *write_ref_log_details)
{
struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
unsigned char *sha1 = xmalloc(targets * 20);
char *msg;
int ret;
int i;
save_commit_buffer = 0;
for (i = 0; i < targets; i++) {
if (!write_ref || !write_ref[i])
continue;
lock[i] = lock_ref_sha1(write_ref[i], NULL);
if (!lock[i]) {
error("Can't lock ref %s", write_ref[i]);
goto unlock_and_fail;
}
}
if (!walker->get_recover)
for_each_ref(mark_complete, NULL);
for (i = 0; i < targets; i++) {
if (interpret_target(walker, target[i], &sha1[20 * i])) {
error("Could not interpret response from server '%s' as something to pull", target[i]);
goto unlock_and_fail;
}
if (process(walker, lookup_unknown_object(&sha1[20 * i])))
goto unlock_and_fail;
}
if (loop(walker))
goto unlock_and_fail;
if (write_ref_log_details) {
msg = xmalloc(strlen(write_ref_log_details) + 12);
sprintf(msg, "fetch from %s", write_ref_log_details);
} else {
msg = NULL;
}
for (i = 0; i < targets; i++) {
if (!write_ref || !write_ref[i])
continue;
ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
lock[i] = NULL;
if (ret)
goto unlock_and_fail;
}
free(msg);
return 0;
unlock_and_fail:
for (i = 0; i < targets; i++)
if (lock[i])
unlock_ref(lock[i]);
return -1;
}
void walker_free(struct walker *walker)
{
walker->cleanup(walker);
free(walker);
}
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