Skip to content

Commit

Permalink
Remove "tree->entries" tree-entry list from tree parser
Browse files Browse the repository at this point in the history 
Instead, just use the tree buffer directly, and use the tree-walk
infrastructure to walk the buffers instead of the tree-entry list.

The tree-entry list is inefficient, and generates tons of small
allocations for no good reason. The tree-walk infrastructure is
generally no harder to use than following a linked list, and allows
us to do most tree parsing in-place.

Some programs still use the old tree-entry lists, and are a bit
painful to convert without major surgery. For them we have a helper
function that creates a temporary tree-entry list on demand.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
  • Loading branch information
Linus Torvalds authored and Junio C Hamano committed May 30, 2006
1 parent 1ccf5a3 commit 2d9c58c
Show file tree
Hide file tree
Showing 9 changed files with 116 additions and 57 deletions.
2 changes: 1 addition & 1 deletion builtin-ls-tree.c
View file
Expand Up @@ -53,7 +53,7 @@ static int show_recursive(const char *base, int baselen, const char *pathname)
}
}

static int show_tree(unsigned char *sha1, const char *base, int baselen,
static int show_tree(const unsigned char *sha1, const char *base, int baselen,
const char *pathname, unsigned mode, int stage)
{
int retval = 0;
Expand Down
4 changes: 2 additions & 2 deletions builtin-read-tree.c
View file
Expand Up @@ -165,7 +165,7 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
struct tree *tree = lookup_tree(posns[i]->sha1);
any_dirs = 1;
parse_tree(tree);
subposns[i] = tree->entries;
subposns[i] = create_tree_entry_list(tree);
posns[i] = posns[i]->next;
src[i + merge] = &df_conflict_entry;
continue;
Expand Down Expand Up @@ -370,7 +370,7 @@ static int unpack_trees(merge_fn_t fn)
if (len) {
posns = xmalloc(len * sizeof(struct tree_entry_list *));
for (i = 0; i < len; i++) {
posns[i] = ((struct tree *) posn->item)->entries;
posns[i] = create_tree_entry_list((struct tree *) posn->item);
posn = posn->next;
}
if (unpack_trees_rec(posns, len, "", fn, &indpos))
Expand Down
26 changes: 16 additions & 10 deletions builtin-rev-list.c
View file
Expand Up @@ -113,7 +113,7 @@ static struct object_list **process_tree(struct tree *tree,
const char *name)
{
struct object *obj = &tree->object;
struct tree_entry_list *entry;
struct tree_desc desc;
struct name_path me;

if (!revs.tree_objects)
Expand All @@ -128,16 +128,22 @@ static struct object_list **process_tree(struct tree *tree,
me.up = path;
me.elem = name;
me.elem_len = strlen(name);
entry = tree->entries;
tree->entries = NULL;
while (entry) {
struct tree_entry_list *next = entry->next;
if (entry->directory)
p = process_tree(lookup_tree(entry->sha1), p, &me, entry->name);

desc.buf = tree->buffer;
desc.size = tree->size;

while (desc.size) {
unsigned mode;
const char *name;
const unsigned char *sha1;

sha1 = tree_entry_extract(&desc, &name, &mode);
update_tree_entry(&desc);

if (S_ISDIR(mode))
p = process_tree(lookup_tree(sha1), p, &me, name);
else
p = process_blob(lookup_blob(entry->sha1), p, &me, entry->name);
free(entry);
entry = next;
p = process_blob(lookup_blob(sha1), p, &me, name);
}
free(tree->buffer);
tree->buffer = NULL;
Expand Down
16 changes: 11 additions & 5 deletions fetch.c
View file
Expand Up @@ -41,16 +41,22 @@ static int process_tree(struct tree *tree)
if (parse_tree(tree))
return -1;

entry = tree->entries;
tree->entries = NULL;
entry = create_tree_entry_list(tree);
while (entry) {
struct tree_entry_list *next = entry->next;
if (process(entry->item.any))
return -1;
free(entry->name);

if (entry->directory) {
struct tree *tree = lookup_tree(entry->sha1);
process_tree(tree);
} else {
struct blob *blob = lookup_blob(entry->sha1);
process(&blob->object);
}
free(entry);
entry = next;
}
free(tree->buffer);
tree->buffer = NULL;
return 0;
}

Expand Down
7 changes: 5 additions & 2 deletions fsck-objects.c
View file
Expand Up @@ -11,6 +11,7 @@
#include "cache-tree.h"

#define REACHABLE 0x0001
#define SEEN 0x0002

static int show_root = 0;
static int show_tags = 0;
Expand Down Expand Up @@ -161,7 +162,7 @@ static int fsck_tree(struct tree *item)
struct tree_entry_list *entry, *last;

last = NULL;
for (entry = item->entries; entry; entry = entry->next) {
for (entry = create_tree_entry_list(item); entry; entry = entry->next) {
if (strchr(entry->name, '/'))
has_full_path = 1;
has_zero_pad |= entry->zeropad;
Expand Down Expand Up @@ -205,7 +206,6 @@ static int fsck_tree(struct tree *item)
}
if (last)
free(last);
item->entries = NULL;
free(item->buffer);
item->buffer = NULL;

Expand Down Expand Up @@ -277,6 +277,9 @@ static int fsck_sha1(unsigned char *sha1)
struct object *obj = parse_object(sha1);
if (!obj)
return error("%s: object not found", sha1_to_hex(sha1));
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (obj->type == blob_type)
return 0;
if (obj->type == tree_type)
Expand Down
30 changes: 20 additions & 10 deletions http-push.c
View file
Expand Up @@ -1704,6 +1704,7 @@ static struct object_list **process_blob(struct blob *blob,
return p;

obj->flags |= SEEN;
name = strdup(name);
return add_object(obj, p, path, name);
}

Expand All @@ -1713,7 +1714,7 @@ static struct object_list **process_tree(struct tree *tree,
const char *name)
{
struct object *obj = &tree->object;
struct tree_entry_list *entry;
struct tree_desc desc;
struct name_path me;

obj->flags |= LOCAL;
Expand All @@ -1724,21 +1725,30 @@ static struct object_list **process_tree(struct tree *tree,
die("bad tree object %s", sha1_to_hex(obj->sha1));

obj->flags |= SEEN;
name = strdup(name);
p = add_object(obj, p, NULL, name);
me.up = path;
me.elem = name;
me.elem_len = strlen(name);
entry = tree->entries;
tree->entries = NULL;
while (entry) {
struct tree_entry_list *next = entry->next;
if (entry->directory)
p = process_tree(lookup_tree(entry->sha1), p, &me, entry->name);

desc.buf = tree->buffer;
desc.size = tree->size;

while (desc.size) {
unsigned mode;
const char *name;
const unsigned char *sha1;

sha1 = tree_entry_extract(&desc, &name, &mode);
update_tree_entry(&desc);

if (S_ISDIR(mode))
p = process_tree(lookup_tree(sha1), p, &me, name);
else
p = process_blob(lookup_blob(entry->sha1), p, &me, entry->name);
free(entry);
entry = next;
p = process_blob(lookup_blob(sha1), p, &me, name);
}
free(tree->buffer);
tree->buffer = NULL;
return p;
}

Expand Down
3 changes: 1 addition & 2 deletions revision.c
View file
Expand Up @@ -63,8 +63,7 @@ void mark_tree_uninteresting(struct tree *tree)
return;
if (parse_tree(tree) < 0)
die("bad tree %s", sha1_to_hex(obj->sha1));
entry = tree->entries;
tree->entries = NULL;
entry = create_tree_entry_list(tree);
while (entry) {
struct tree_entry_list *next = entry->next;
if (entry->directory)
Expand Down
81 changes: 57 additions & 24 deletions tree.c
View file
Expand Up @@ -151,22 +151,65 @@ struct tree *lookup_tree(const unsigned char *sha1)
return (struct tree *) obj;
}

int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
static int track_tree_refs(struct tree *item)
{
int n_refs = 0, i;
struct object_refs *refs;
struct tree_desc desc;
struct tree_entry_list **list_p;
int n_refs = 0;

/* Count how many entries there are.. */
desc.buf = item->buffer;
desc.size = item->size;
while (desc.size) {
n_refs++;
update_tree_entry(&desc);
}

/* Allocate object refs and walk it again.. */
i = 0;
refs = alloc_object_refs(n_refs);
desc.buf = item->buffer;
desc.size = item->size;
while (desc.size) {
unsigned mode;
const char *name;
const unsigned char *sha1;
struct object *obj;

sha1 = tree_entry_extract(&desc, &name, &mode);
update_tree_entry(&desc);
if (S_ISDIR(mode))
obj = &lookup_tree(sha1)->object;
else
obj = &lookup_blob(sha1)->object;
refs->ref[i++] = obj;
}
set_object_refs(&item->object, refs);
return 0;
}

int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
{
if (item->object.parsed)
return 0;
item->object.parsed = 1;
item->buffer = buffer;
item->size = size;

desc.buf = buffer;
desc.size = size;
if (track_object_refs)
track_tree_refs(item);
return 0;
}

struct tree_entry_list *create_tree_entry_list(struct tree *tree)
{
struct tree_desc desc;
struct tree_entry_list *ret = NULL;
struct tree_entry_list **list_p = &ret;

desc.buf = tree->buffer;
desc.size = tree->size;

list_p = &item->entries;
while (desc.size) {
unsigned mode;
const char *path;
Expand All @@ -186,29 +229,19 @@ int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
entry->next = NULL;

update_tree_entry(&desc);
n_refs++;
*list_p = entry;
list_p = &entry->next;
}
return ret;
}

if (track_object_refs) {
struct tree_entry_list *entry;
unsigned i = 0;
struct object_refs *refs = alloc_object_refs(n_refs);
for (entry = item->entries; entry; entry = entry->next) {
struct object *obj;

if (entry->directory)
obj = &lookup_tree(entry->sha1)->object;
else
obj = &lookup_blob(entry->sha1)->object;
refs->ref[i++] = obj;
}

set_object_refs(&item->object, refs);
void free_tree_entry_list(struct tree_entry_list *list)
{
while (list) {
struct tree_entry_list *next = list->next;
free(list);
list = next;
}

return 0;
}

int parse_tree(struct tree *item)
Expand Down
4 changes: 3 additions & 1 deletion tree.h
View file
Expand Up @@ -20,9 +20,11 @@ struct tree {
struct object object;
void *buffer;
unsigned long size;
struct tree_entry_list *entries;
};

struct tree_entry_list *create_tree_entry_list(struct tree *);
void free_tree_entry_list(struct tree_entry_list *);

struct tree *lookup_tree(const unsigned char *sha1);

int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size);
Expand Down

0 comments on commit 2d9c58c

Please sign in to comment.