Revision 24ff4d56cf400126aa93ac9a5b9d8a21afadf3f6 authored by Björn Gustavsson on 06 March 2010, 14:30:29 UTC, committed by Junio C Hamano on 07 March 2010, 07:53:00 UTC
In the next commit, we will make it possible for blank context
lines to match beyond the end of the file. That means that a hunk
with a preimage that has more lines than present in the file may
be possible to successfully apply. Therefore, we must remove
the quick rejection test in find_pos().

find_pos() will already work correctly without the quick
rejection test, but that might not be obvious. Therefore,
comment the test for handling out-of-range line numbers in
find_pos() and cast the "line" variable to the same (unsigned)
type as img->nr.

What are performance implications of removing the quick
rejection test?

It can only help "git apply" to reject a patch faster. For example,
if I have a file with one million lines and a patch that removes
slightly more than 50 percent of the lines and try to apply that
patch twice, the second attempt will fail slightly faster
with the test than without (based on actual measurements).

However, there is the pathological case of a patch with many
more context lines than the default three, and applying that patch
using "git apply -C1". Without the rejection test, the running
time will be roughly proportional to the number of context lines
times the size of the file. That could be handled by writing
a more complicated rejection test (it would have to count the
number of blanks at the end of the preimage), but I don't find
that worth doing until there is a real-world use case that
would benfit from it.

It would be possible to keep the quick rejection test if
--whitespace=fix is not given, but I don't like that from
a testing point of view.

Signed-off-by: Björn Gustavsson <bgustavsson@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 9b25949
Raw File
remote.h
#ifndef REMOTE_H
#define REMOTE_H

enum {
	REMOTE_CONFIG,
	REMOTE_REMOTES,
	REMOTE_BRANCHES
};

struct remote {
	const char *name;
	int origin;

	const char *foreign_vcs;

	const char **url;
	int url_nr;
	int url_alloc;

	const char **pushurl;
	int pushurl_nr;
	int pushurl_alloc;

	const char **push_refspec;
	struct refspec *push;
	int push_refspec_nr;
	int push_refspec_alloc;

	const char **fetch_refspec;
	struct refspec *fetch;
	int fetch_refspec_nr;
	int fetch_refspec_alloc;

	/*
	 * -1 to never fetch tags
	 * 0 to auto-follow tags on heuristic (default)
	 * 1 to always auto-follow tags
	 * 2 to always fetch tags
	 */
	int fetch_tags;
	int skip_default_update;
	int mirror;

	const char *receivepack;
	const char *uploadpack;

	/*
	 * for curl remotes only
	 */
	char *http_proxy;
};

struct remote *remote_get(const char *name);
int remote_is_configured(const char *name);

typedef int each_remote_fn(struct remote *remote, void *priv);
int for_each_remote(each_remote_fn fn, void *priv);

int remote_has_url(struct remote *remote, const char *url);

struct refspec {
	unsigned force : 1;
	unsigned pattern : 1;
	unsigned matching : 1;

	char *src;
	char *dst;
};

extern const struct refspec *tag_refspec;

struct ref *alloc_ref(const char *name);

struct ref *copy_ref_list(const struct ref *ref);

int check_ref_type(const struct ref *ref, int flags);

/*
 * Frees the entire list and peers of elements.
 */
void free_refs(struct ref *ref);

int resolve_remote_symref(struct ref *ref, struct ref *list);
int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1);

/*
 * Removes and frees any duplicate refs in the map.
 */
void ref_remove_duplicates(struct ref *ref_map);

int valid_fetch_refspec(const char *refspec);
struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec);

void free_refspec(int nr_refspec, struct refspec *refspec);

char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
		     const char *name);

int match_refs(struct ref *src, struct ref **dst,
	       int nr_refspec, const char **refspec, int all);
void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
	int force_update);

/*
 * Given a list of the remote refs and the specification of things to
 * fetch, makes a (separate) list of the refs to fetch and the local
 * refs to store into.
 *
 * *tail is the pointer to the tail pointer of the list of results
 * beforehand, and will be set to the tail pointer of the list of
 * results afterward.
 *
 * missing_ok is usually false, but when we are adding branch.$name.merge
 * it is Ok if the branch is not at the remote anymore.
 */
int get_fetch_map(const struct ref *remote_refs, const struct refspec *refspec,
		  struct ref ***tail, int missing_ok);

struct ref *get_remote_ref(const struct ref *remote_refs, const char *name);

/*
 * For the given remote, reads the refspec's src and sets the other fields.
 */
int remote_find_tracking(struct remote *remote, struct refspec *refspec);

struct branch {
	const char *name;
	const char *refname;

	const char *remote_name;
	struct remote *remote;

	const char **merge_name;
	struct refspec **merge;
	int merge_nr;
	int merge_alloc;
};

struct branch *branch_get(const char *name);

int branch_has_merge_config(struct branch *branch);
int branch_merge_matches(struct branch *, int n, const char *);

/* Flags to match_refs. */
enum match_refs_flags {
	MATCH_REFS_NONE		= 0,
	MATCH_REFS_ALL 		= (1 << 0),
	MATCH_REFS_MIRROR	= (1 << 1),
};

/* Reporting of tracking info */
int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs);
int format_tracking_info(struct branch *branch, struct strbuf *sb);

struct ref *get_local_heads(void);
/*
 * Find refs from a list which are likely to be pointed to by the given HEAD
 * ref. If 'all' is false, returns the most likely ref; otherwise, returns a
 * list of all candidate refs. If no match is found (or 'head' is NULL),
 * returns NULL. All returns are newly allocated and should be freed.
 */
struct ref *guess_remote_head(const struct ref *head,
			      const struct ref *refs,
			      int all);

/* Return refs which no longer exist on remote */
struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map);

#endif
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