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8ff226a9d5
When we call lookup_commit, lookup_tree, etc, the logic goes
something like:
1. Look for an existing object struct. If we don't have
one, allocate and return a new one.
2. Double check that any object we have is the expected
type (and complain and return NULL otherwise).
3. Convert an object with type OBJ_NONE (from a prior
call to lookup_unknown_object) to the expected type.
We can encapsulate steps 2 and 3 in a helper function which
checks whether we have the expected object type, converts
OBJ_NONE as appropriate, and returns the object.
Not only does this shorten the code, but it also provides
one central location for converting OBJ_NONE objects into
objects of other types. Future patches will use that to
enforce type-specific invariants.
Since this is a refactoring, we would want it to behave
exactly as the current code. It takes a little reasoning to
see that this is the case:
- for lookup_{commit,tree,etc} functions, we are just
pulling steps 2 and 3 into a function that does the same
thing.
- for the call in peel_object, we currently only do step 3
(but we want to consolidate it with the others, as
mentioned above). However, step 2 is a noop here, as the
surrounding conditional makes sure we have OBJ_NONE
(which we want to keep to avoid an extraneous call to
sha1_object_info).
- for the call in lookup_commit_reference_gently, we are
currently doing step 2 but not step 3. However, step 3
is a noop here. The object we got will have just come
from deref_tag, which must have figured out the type for
each object in order to know when to stop peeling.
Therefore the type will never be OBJ_NONE.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
162 lines
3.8 KiB
C
162 lines
3.8 KiB
C
#include "cache.h"
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#include "tag.h"
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#include "commit.h"
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#include "tree.h"
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#include "blob.h"
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#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
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#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
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const char *tag_type = "tag";
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struct object *deref_tag(struct object *o, const char *warn, int warnlen)
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{
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while (o && o->type == OBJ_TAG)
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if (((struct tag *)o)->tagged)
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o = parse_object(((struct tag *)o)->tagged->sha1);
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else
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o = NULL;
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if (!o && warn) {
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if (!warnlen)
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warnlen = strlen(warn);
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error("missing object referenced by '%.*s'", warnlen, warn);
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}
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return o;
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}
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struct object *deref_tag_noverify(struct object *o)
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{
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while (o && o->type == OBJ_TAG) {
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o = parse_object(o->sha1);
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if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
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o = ((struct tag *)o)->tagged;
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else
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o = NULL;
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}
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return o;
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}
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struct tag *lookup_tag(const unsigned char *sha1)
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{
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struct object *obj = lookup_object(sha1);
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if (!obj)
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return create_object(sha1, alloc_tag_node());
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return object_as_type(obj, OBJ_TAG, 0);
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}
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static unsigned long parse_tag_date(const char *buf, const char *tail)
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{
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const char *dateptr;
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while (buf < tail && *buf++ != '>')
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/* nada */;
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if (buf >= tail)
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return 0;
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dateptr = buf;
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while (buf < tail && *buf++ != '\n')
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/* nada */;
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if (buf >= tail)
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return 0;
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/* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
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return strtoul(dateptr, NULL, 10);
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}
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int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
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{
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unsigned char sha1[20];
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char type[20];
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const char *bufptr = data;
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const char *tail = bufptr + size;
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const char *nl;
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if (item->object.parsed)
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return 0;
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item->object.parsed = 1;
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if (size < 64)
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return -1;
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if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
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return -1;
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bufptr += 48; /* "object " + sha1 + "\n" */
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if (!starts_with(bufptr, "type "))
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return -1;
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bufptr += 5;
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nl = memchr(bufptr, '\n', tail - bufptr);
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if (!nl || sizeof(type) <= (nl - bufptr))
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return -1;
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strncpy(type, bufptr, nl - bufptr);
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type[nl - bufptr] = '\0';
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bufptr = nl + 1;
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if (!strcmp(type, blob_type)) {
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item->tagged = &lookup_blob(sha1)->object;
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} else if (!strcmp(type, tree_type)) {
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item->tagged = &lookup_tree(sha1)->object;
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} else if (!strcmp(type, commit_type)) {
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item->tagged = &lookup_commit(sha1)->object;
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} else if (!strcmp(type, tag_type)) {
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item->tagged = &lookup_tag(sha1)->object;
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} else {
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error("Unknown type %s", type);
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item->tagged = NULL;
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}
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if (bufptr + 4 < tail && starts_with(bufptr, "tag "))
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; /* good */
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else
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return -1;
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bufptr += 4;
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nl = memchr(bufptr, '\n', tail - bufptr);
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if (!nl)
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return -1;
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item->tag = xmemdupz(bufptr, nl - bufptr);
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bufptr = nl + 1;
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if (bufptr + 7 < tail && starts_with(bufptr, "tagger "))
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item->date = parse_tag_date(bufptr, tail);
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else
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item->date = 0;
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return 0;
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}
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int parse_tag(struct tag *item)
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{
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enum object_type type;
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void *data;
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unsigned long size;
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int ret;
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if (item->object.parsed)
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return 0;
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data = read_sha1_file(item->object.sha1, &type, &size);
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if (!data)
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return error("Could not read %s",
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sha1_to_hex(item->object.sha1));
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if (type != OBJ_TAG) {
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free(data);
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return error("Object %s not a tag",
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sha1_to_hex(item->object.sha1));
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}
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ret = parse_tag_buffer(item, data, size);
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free(data);
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return ret;
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}
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/*
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* Look at a signed tag object, and return the offset where
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* the embedded detached signature begins, or the end of the
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* data when there is no such signature.
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*/
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size_t parse_signature(const char *buf, unsigned long size)
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{
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char *eol;
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size_t len = 0;
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while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
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!starts_with(buf + len, PGP_MESSAGE)) {
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eol = memchr(buf + len, '\n', size - len);
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len += eol ? eol - (buf + len) + 1 : size - len;
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}
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return len;
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}
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