git/tree-walk.h

#ifndef TREE_WALK_H
#define TREE_WALK_H

#include "hash.h"

struct index_state;
struct repository;

/**
 * The tree walking API is used to traverse and inspect trees.
 */

/**
 * An entry in a tree. Each entry has a sha1 identifier, pathname, and mode.
 */
struct name_entry { … };

/**
 * A semi-opaque data structure used to maintain the current state of the walk.
 */
struct tree_desc { … };

/**
 * Decode the entry currently being visited (the one pointed to by
 * `tree_desc's` `entry` member) and return the sha1 of the entry. The
 * `pathp` and `modep` arguments are set to the entry's pathname and mode
 * respectively.
 */
static inline const struct object_id *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned short *modep)
{ … }

/**
 * Calculate the length of a tree entry's pathname. This utilizes the
 * memory structure of a tree entry to avoid the overhead of using a
 * generic strlen().
 */
static inline int tree_entry_len(const struct name_entry *ne)
{ … }

/*
 * The _gently versions of these functions warn and return false on a
 * corrupt tree entry rather than dying,
 */

/**
 * Walk to the next entry in a tree. This is commonly used in conjunction
 * with `tree_entry_extract` to inspect the current entry.
 */
void update_tree_entry(struct tree_desc *);

int update_tree_entry_gently(struct tree_desc *);

/**
 * Initialize a `tree_desc` and decode its first entry. The buffer and
 * size parameters are assumed to be the same as the buffer and size
 * members of `struct tree`.
 */
void init_tree_desc(struct tree_desc *desc, const struct object_id *tree_oid,
		    const void *buf, unsigned long size);

int init_tree_desc_gently(struct tree_desc *desc, const struct object_id *oid,
			  const void *buf, unsigned long size,
			  enum tree_desc_flags flags);

/*
 * Visit the next entry in a tree. Returns 1 when there are more entries
 * left to visit and 0 when all entries have been visited. This is
 * commonly used in the test of a while loop.
 */
int tree_entry(struct tree_desc *, struct name_entry *);

int tree_entry_gently(struct tree_desc *, struct name_entry *);

/**
 * Initialize a `tree_desc` and decode its first entry given the
 * object ID of a tree. Returns the `buffer` member if the latter
 * is a valid tree identifier and NULL otherwise.
 */
void *fill_tree_descriptor(struct repository *r,
			   struct tree_desc *desc,
			   const struct object_id *oid);

struct traverse_info;
traverse_callback_t;

/**
 * Traverse `n` number of trees in parallel. The `fn` callback member of
 * `traverse_info` is called once for each tree entry.
 */
int traverse_trees(struct index_state *istate, int n, struct tree_desc *t, struct traverse_info *info);

enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r, struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned short *mode);

/**
 * A structure used to maintain the state of a traversal.
 */
struct traverse_info { … };

/**
 * Find an entry in a tree given a pathname and the sha1 of a tree to
 * search. Returns 0 if the entry is found and -1 otherwise. The third
 * and fourth parameters are set to the entry's sha1 and mode respectively.
 */
int get_tree_entry(struct repository *, const struct object_id *, const char *, struct object_id *, unsigned short *);

/**
 * Generate the full pathname of a tree entry based from the root of the
 * traversal. For example, if the traversal has recursed into another
 * tree named "bar" the pathname of an entry "baz" in the "bar"
 * tree would be "bar/baz".
 */
char *make_traverse_path(char *path, size_t pathlen, const struct traverse_info *info,
			 const char *name, size_t namelen);

/**
 * Convenience wrapper to `make_traverse_path` into a strbuf.
 */
void strbuf_make_traverse_path(struct strbuf *out,
			       const struct traverse_info *info,
			       const char *name, size_t namelen);

/**
 * Initialize a `traverse_info` given the pathname of the tree to start
 * traversing from.
 */
void setup_traverse_info(struct traverse_info *info, const char *base);

/**
 * Calculate the length of a pathname returned by `make_traverse_path`.
 * This utilizes the memory structure of a tree entry to avoid the
 * overhead of using a generic strlen().
 */
static inline size_t traverse_path_len(const struct traverse_info *info,
				       size_t namelen)
{ … }

/* in general, positive means "kind of interesting" */
enum interesting { … };

enum interesting tree_entry_interesting(struct index_state *istate,
					const struct name_entry *,
					struct strbuf *,
					const struct pathspec *ps);

#endif