commit.c - pub/scm/git/git - Git at Google

 #include <ctype.h>
 #include "tag.h"
 #include "commit.h"
 #include "cache.h"

 struct sort_node
 {
 	/*
          * the number of children of the associated commit
          * that also occur in the list being sorted.
          */
 	unsigned int indegree;

 	/*
          * reference to original list item that we will re-use
          * on output.
          */
 	struct commit_list * list_item;

 };

 const char *commit_type = "commit";

 enum cmit_fmt get_commit_format(const char *arg)
 {
 	if (!*arg)
 		return CMIT_FMT_DEFAULT;
 	if (!strcmp(arg, "=raw"))
 		return CMIT_FMT_RAW;
 	if (!strcmp(arg, "=medium"))
 		return CMIT_FMT_MEDIUM;
 	if (!strcmp(arg, "=short"))
 		return CMIT_FMT_SHORT;
 	if (!strcmp(arg, "=full"))
 		return CMIT_FMT_FULL;
 	die("invalid --pretty format");
 }

 static struct commit *check_commit(struct object *obj, const unsigned char *sha1)
 {
 	if (obj->type != commit_type) {
 		error("Object %s is a %s, not a commit",
 		      sha1_to_hex(sha1), obj->type);
 		return NULL;
 	}
 	return (struct commit *) obj;
 }

 struct commit *lookup_commit_reference(const unsigned char *sha1)
 {
 	struct object *obj = parse_object(sha1);

 	if (!obj)
 		return NULL;
 	while (obj->type == tag_type)
 		obj = parse_object(((struct tag *)obj)->tagged->sha1);

 	return check_commit(obj, sha1);
 }

 struct commit *lookup_commit(const unsigned char *sha1)
 {
 	struct object *obj = lookup_object(sha1);
 	if (!obj) {
 		struct commit *ret = xmalloc(sizeof(struct commit));
 		memset(ret, 0, sizeof(struct commit));
 		created_object(sha1, &ret->object);
 		ret->object.type = commit_type;
 		return ret;
 	}
 	if (!obj->type)
 		obj->type = commit_type;
 	return check_commit(obj, sha1);
 }

 static unsigned long parse_commit_date(const char *buf)
 {
 	unsigned long date;

 	if (memcmp(buf, "author", 6))
 		return 0;
 	while (*buf++ != '\n')
 		/* nada */;
 	if (memcmp(buf, "committer", 9))
 		return 0;
 	while (*buf++ != '>')
 		/* nada */;
 	date = strtoul(buf, NULL, 10);
 	if (date == ULONG_MAX)
 		date = 0;
 	return date;
 }

 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 {
 	void *bufptr = buffer;
 	unsigned char parent[20];
 	struct commit_list **pptr;

 	if (item->object.parsed)
 		return 0;
 	item->object.parsed = 1;
 	get_sha1_hex(bufptr + 5, parent);
 	item->tree = lookup_tree(parent);
 	if (item->tree)
 		add_ref(&item->object, &item->tree->object);
 	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 	pptr = &item->parents;
 	while (!memcmp(bufptr, "parent ", 7) &&
 	       !get_sha1_hex(bufptr + 7, parent)) {
 		struct commit *new_parent = lookup_commit(parent);
 		if (new_parent) {
 			pptr = &commit_list_insert(new_parent, pptr)->next;
 			add_ref(&item->object, &new_parent->object);
 		}
 		bufptr += 48;
 	}
 	item->date = parse_commit_date(bufptr);
 	return 0;
 }

 int parse_commit(struct commit *item)
 {
 	char type[20];
 	void *buffer;
 	unsigned long size;
 	int ret;

 	if (item->object.parsed)
 		return 0;
 	buffer = read_sha1_file(item->object.sha1, type, &size);
 	if (!buffer)
 		return error("Could not read %s",
 			     sha1_to_hex(item->object.sha1));
 	if (strcmp(type, commit_type)) {
 		free(buffer);
 		return error("Object %s not a commit",
 			     sha1_to_hex(item->object.sha1));
 	}
 	ret = parse_commit_buffer(item, buffer, size);
 	if (!ret) {
 		item->buffer = buffer;
 		return 0;
 	}
 	free(buffer);
 	return ret;
 }

 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 {
 	struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 	new_list->item = item;
 	new_list->next = *list_p;
 	*list_p = new_list;
 	return new_list;
 }

 void free_commit_list(struct commit_list *list)
 {
 	while (list) {
 		struct commit_list *temp = list;
 		list = temp->next;
 		free(temp);
 	}
 }

 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 {
 	struct commit_list **pp = list;
 	struct commit_list *p;
 	while ((p = *pp) != NULL) {
 		if (p->item->date < item->date) {
 			break;
 		}
 		pp = &p->next;
 	}
 	return commit_list_insert(item, pp);
 }


 void sort_by_date(struct commit_list **list)
 {
 	struct commit_list *ret = NULL;
 	while (*list) {
 		insert_by_date((*list)->item, &ret);
 		*list = (*list)->next;
 	}
 	*list = ret;
 }

 struct commit *pop_most_recent_commit(struct commit_list **list,
 				      unsigned int mark)
 {
 	struct commit *ret = (*list)->item;
 	struct commit_list *parents = ret->parents;
 	struct commit_list *old = *list;

 	*list = (*list)->next;
 	free(old);

 	while (parents) {
 		struct commit *commit = parents->item;
 		parse_commit(commit);
 		if (!(commit->object.flags & mark)) {
 			commit->object.flags |= mark;
 			insert_by_date(commit, list);
 		}
 		parents = parents->next;
 	}
 	return ret;
 }

 /*
  * Generic support for pretty-printing the header
  */
 static int get_one_line(const char *msg, unsigned long len)
 {
 	int ret = 0;

 	while (len--) {
 		char c = *msg++;
 		ret++;
 		if (c == '\n')
 			break;
 		if (!c)
 			return 0;
 	}
 	return ret;
 }

 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 {
 	char *date;
 	unsigned int namelen;
 	unsigned long time;
 	int tz, ret;

 	date = strchr(line, '>');
 	if (!date)
 		return 0;
 	namelen = ++date - line;
 	time = strtoul(date, &date, 10);
 	tz = strtol(date, NULL, 10);

 	ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 	if (fmt == CMIT_FMT_MEDIUM)
 		ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 	return ret;
 }

 static int is_empty_line(const char *line, int len)
 {
 	while (len && isspace(line[len-1]))
 		len--;
 	return !len;
 }

 static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 {
 	int offset = 0;
 	switch (parents) {
 	case 1:
 		break;
 	case 2:
 		/* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 		offset = sprintf(buf, "Merge: %.40s\n", line-41);
 		/* Fallthrough */
 	default:
 		/* Replace the previous '\n' with a space */
 		buf[offset-1] = ' ';
 		offset += sprintf(buf + offset, "%.40s\n", line+7);
 	}
 	return offset;
 }

 unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 {
 	int hdr = 1, body = 0;
 	unsigned long offset = 0;
 	int parents = 0;

 	for (;;) {
 		const char *line = msg;
 		int linelen = get_one_line(msg, len);

 		if (!linelen)
 			break;

 		/*
 		 * We want some slop for indentation and a possible
 		 * final "...". Thus the "+ 20".
 		 */
 		if (offset + linelen + 20 > space) {
 			memcpy(buf + offset, "    ...\n", 8);
 			offset += 8;
 			break;
 		}

 		msg += linelen;
 		len -= linelen;
 		if (hdr) {
 			if (linelen == 1) {
 				hdr = 0;
 				buf[offset++] = '\n';
 				continue;
 			}
 			if (fmt == CMIT_FMT_RAW) {
 				memcpy(buf + offset, line, linelen);
 				offset += linelen;
 				continue;
 			}
 			if (!memcmp(line, "parent ", 7)) {
 				if (linelen != 48)
 					die("bad parent line in commit");
 				offset += add_parent_info(fmt, buf + offset, line, ++parents);
 			}
 			if (!memcmp(line, "author ", 7))
 				offset += add_user_info("Author", fmt, buf + offset, line + 7);
 			if (fmt == CMIT_FMT_FULL) {
 				if (!memcmp(line, "committer ", 10))
 					offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 			}
 			continue;
 		}

 		if (is_empty_line(line, linelen)) {
 			if (!body)
 				continue;
 			if (fmt == CMIT_FMT_SHORT)
 				break;
 		} else {
 			body = 1;
 		}
 		memset(buf + offset, ' ', 4);
 		memcpy(buf + offset + 4, line, linelen);
 		offset += linelen + 4;
 	}
 	/* Make sure there is an EOLN */
 	if (buf[offset - 1] != '\n')
 		buf[offset++] = '\n';
 	buf[offset] = '\0';
 	return offset;
 }

 struct commit *pop_commit(struct commit_list **stack)
 {
 	struct commit_list *top = *stack;
 	struct commit *item = top ? top->item : NULL;

 	if (top) {
 		*stack = top->next;
 		free(top);
 	}
 	return item;
 }

 int count_parents(struct commit * commit)
 {
         int count = 0;
         struct commit_list * parents = commit->parents;
         for (count=0;parents; parents=parents->next,count++)
           ;
         return count;
 }

 /*
  * Performs an in-place topological sort on the list supplied.
  */
 void sort_in_topological_order(struct commit_list ** list)
 {
 	struct commit_list * next = *list;
 	struct commit_list * work = NULL;
 	struct commit_list ** pptr = list;
 	struct sort_node * nodes;
 	struct sort_node * next_nodes;
 	int count = 0;

 	/* determine the size of the list */
 	while (next) {
 		next = next->next;
 		count++;
 	}
 	/* allocate an array to help sort the list */
 	nodes = xcalloc(count, sizeof(*nodes));
 	/* link the list to the array */
 	next_nodes = nodes;
 	next=*list;
 	while (next) {
 		next_nodes->list_item = next;
 		next->item->object.util = next_nodes;
 		next_nodes++;
 		next = next->next;
 	}
 	/* update the indegree */
 	next=*list;
 	while (next) {
 		struct commit_list * parents = next->item->parents;
 		while (parents) {
 			struct commit * parent=parents->item;
 			struct sort_node * pn = (struct sort_node *)parent->object.util;

 			if (pn)
 				pn->indegree++;
 			parents=parents->next;
 		}
 		next=next->next;
 	}
 	/*
          * find the tips
          *
          * tips are nodes not reachable from any other node in the list
          *
          * the tips serve as a starting set for the work queue.
          */
 	next=*list;
 	while (next) {
 		struct sort_node * node = (struct sort_node *)next->item->object.util;

 		if (node->indegree == 0) {
 			commit_list_insert(next->item, &work);
 		}
 		next=next->next;
 	}
 	/* process the list in topological order */
 	while (work) {
 		struct commit * work_item = pop_commit(&work);
 		struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 		struct commit_list * parents = work_item->parents;

 		while (parents) {
 			struct commit * parent=parents->item;
 			struct sort_node * pn = (struct sort_node *)parent->object.util;

 			if (pn) {
 				/*
 				 * parents are only enqueued for emission
                                  * when all their children have been emitted thereby
                                  * guaranteeing topological order.
                                  */
 				pn->indegree--;
 				if (!pn->indegree)
 					commit_list_insert(parent, &work);
 			}
 			parents=parents->next;
 		}
 		/*
                  * work_item is a commit all of whose children
                  * have already been emitted. we can emit it now.
                  */
 		*pptr = work_node->list_item;
 		pptr = &(*pptr)->next;
 		*pptr = NULL;
 		work_item->object.util = NULL;
 	}
 	free(nodes);
 }
	#include <ctype.h>
	#include "tag.h"
	#include "commit.h"
	#include "cache.h"

	struct sort_node
	{
	/*
	* the number of children of the associated commit
	* that also occur in the list being sorted.
	*/
	unsigned int indegree;

	/*
	* reference to original list item that we will re-use
	* on output.
	*/
	struct commit_list * list_item;

	};

	const char *commit_type = "commit";

	enum cmit_fmt get_commit_format(const char *arg)
	{
	if (!*arg)
	return CMIT_FMT_DEFAULT;
	if (!strcmp(arg, "=raw"))
	return CMIT_FMT_RAW;
	if (!strcmp(arg, "=medium"))
	return CMIT_FMT_MEDIUM;
	if (!strcmp(arg, "=short"))
	return CMIT_FMT_SHORT;
	if (!strcmp(arg, "=full"))
	return CMIT_FMT_FULL;
	die("invalid --pretty format");
	}

	static struct commit check_commit(struct object obj, const unsigned char *sha1)
	{
	if (obj->type != commit_type) {
	error("Object %s is a %s, not a commit",
	sha1_to_hex(sha1), obj->type);
	return NULL;
	}
	return (struct commit *) obj;
	}

	struct commit lookup_commit_reference(const unsigned char sha1)
	{
	struct object *obj = parse_object(sha1);

	if (!obj)
	return NULL;
	while (obj->type == tag_type)
	obj = parse_object(((struct tag *)obj)->tagged->sha1);

	return check_commit(obj, sha1);
	}

	struct commit lookup_commit(const unsigned char sha1)
	{
	struct object *obj = lookup_object(sha1);
	if (!obj) {
	struct commit *ret = xmalloc(sizeof(struct commit));
	memset(ret, 0, sizeof(struct commit));
	created_object(sha1, &ret->object);
	ret->object.type = commit_type;
	return ret;
	}
	if (!obj->type)
	obj->type = commit_type;
	return check_commit(obj, sha1);
	}

	static unsigned long parse_commit_date(const char *buf)
	{
	unsigned long date;

	if (memcmp(buf, "author", 6))
	return 0;
	while (*buf++ != '\n')
	/* nada */;
	if (memcmp(buf, "committer", 9))
	return 0;
	while (*buf++ != '>')
	/* nada */;
	date = strtoul(buf, NULL, 10);
	if (date == ULONG_MAX)
	date = 0;
	return date;
	}

	int parse_commit_buffer(struct commit item, void buffer, unsigned long size)
	{
	void *bufptr = buffer;
	unsigned char parent[20];
	struct commit_list **pptr;

	if (item->object.parsed)
	return 0;
	item->object.parsed = 1;
	get_sha1_hex(bufptr + 5, parent);
	item->tree = lookup_tree(parent);
	if (item->tree)
	add_ref(&item->object, &item->tree->object);
	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
	pptr = &item->parents;
	while (!memcmp(bufptr, "parent ", 7) &&
	!get_sha1_hex(bufptr + 7, parent)) {
	struct commit *new_parent = lookup_commit(parent);
	if (new_parent) {
	pptr = &commit_list_insert(new_parent, pptr)->next;
	add_ref(&item->object, &new_parent->object);
	}
	bufptr += 48;
	}
	item->date = parse_commit_date(bufptr);
	return 0;
	}

	int parse_commit(struct commit *item)
	{
	char type[20];
	void *buffer;
	unsigned long size;
	int ret;

	if (item->object.parsed)
	return 0;
	buffer = read_sha1_file(item->object.sha1, type, &size);
	if (!buffer)
	return error("Could not read %s",
	sha1_to_hex(item->object.sha1));
	if (strcmp(type, commit_type)) {
	free(buffer);
	return error("Object %s not a commit",
	sha1_to_hex(item->object.sha1));
	}
	ret = parse_commit_buffer(item, buffer, size);
	if (!ret) {
	item->buffer = buffer;
	return 0;
	}
	free(buffer);
	return ret;
	}

	struct commit_list commit_list_insert(struct commit item, struct commit_list **list_p)
	{
	struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
	new_list->item = item;
	new_list->next = *list_p;
	*list_p = new_list;
	return new_list;
	}

	void free_commit_list(struct commit_list *list)
	{
	while (list) {
	struct commit_list *temp = list;
	list = temp->next;
	free(temp);
	}
	}

	struct commit_list * insert_by_date(struct commit item, struct commit_list *list)
	{
	struct commit_list **pp = list;
	struct commit_list *p;
	while ((p = *pp) != NULL) {
	if (p->item->date < item->date) {
	break;
	}
	pp = &p->next;
	}
	return commit_list_insert(item, pp);
	}


	void sort_by_date(struct commit_list **list)
	{
	struct commit_list *ret = NULL;
	while (*list) {
	insert_by_date((*list)->item, &ret);
	list = (list)->next;
	}
	*list = ret;
	}

	struct commit pop_most_recent_commit(struct commit_list *list,
	unsigned int mark)
	{
	struct commit ret = (list)->item;
	struct commit_list *parents = ret->parents;
	struct commit_list old = list;

	list = (list)->next;
	free(old);

	while (parents) {
	struct commit *commit = parents->item;
	parse_commit(commit);
	if (!(commit->object.flags & mark)) {
	commit->object.flags \|= mark;
	insert_by_date(commit, list);
	}
	parents = parents->next;
	}
	return ret;
	}

	/*
	* Generic support for pretty-printing the header
	*/
	static int get_one_line(const char *msg, unsigned long len)
	{
	int ret = 0;

	while (len--) {
	char c = *msg++;
	ret++;
	if (c == '\n')
	break;
	if (!c)
	return 0;
	}
	return ret;
	}

	static int add_user_info(const char what, enum cmit_fmt fmt, char buf, const char *line)
	{
	char *date;
	unsigned int namelen;
	unsigned long time;
	int tz, ret;

	date = strchr(line, '>');
	if (!date)
	return 0;
	namelen = ++date - line;
	time = strtoul(date, &date, 10);
	tz = strtol(date, NULL, 10);

	ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
	if (fmt == CMIT_FMT_MEDIUM)
	ret += sprintf(buf + ret, "Date: %s\n", show_date(time, tz));
	return ret;
	}

	static int is_empty_line(const char *line, int len)
	{
	while (len && isspace(line[len-1]))
	len--;
	return !len;
	}

	static int add_parent_info(enum cmit_fmt fmt, char buf, const char line, int parents)
	{
	int offset = 0;
	switch (parents) {
	case 1:
	break;
	case 2:
	/* Go back to the previous line: 40 characters of previous parent, and one '\n' */
	offset = sprintf(buf, "Merge: %.40s\n", line-41);
	/* Fallthrough */
	default:
	/* Replace the previous '\n' with a space */
	buf[offset-1] = ' ';
	offset += sprintf(buf + offset, "%.40s\n", line+7);
	}
	return offset;
	}

	unsigned long pretty_print_commit(enum cmit_fmt fmt, const char msg, unsigned long len, char buf, unsigned long space)
	{
	int hdr = 1, body = 0;
	unsigned long offset = 0;
	int parents = 0;

	for (;;) {
	const char *line = msg;
	int linelen = get_one_line(msg, len);

	if (!linelen)
	break;

	/*
	* We want some slop for indentation and a possible
	* final "...". Thus the "+ 20".
	*/
	if (offset + linelen + 20 > space) {
	memcpy(buf + offset, " ...\n", 8);
	offset += 8;
	break;
	}

	msg += linelen;
	len -= linelen;
	if (hdr) {
	if (linelen == 1) {
	hdr = 0;
	buf[offset++] = '\n';
	continue;
	}
	if (fmt == CMIT_FMT_RAW) {
	memcpy(buf + offset, line, linelen);
	offset += linelen;
	continue;
	}
	if (!memcmp(line, "parent ", 7)) {
	if (linelen != 48)
	die("bad parent line in commit");
	offset += add_parent_info(fmt, buf + offset, line, ++parents);
	}
	if (!memcmp(line, "author ", 7))
	offset += add_user_info("Author", fmt, buf + offset, line + 7);
	if (fmt == CMIT_FMT_FULL) {
	if (!memcmp(line, "committer ", 10))
	offset += add_user_info("Commit", fmt, buf + offset, line + 10);
	}
	continue;
	}

	if (is_empty_line(line, linelen)) {
	if (!body)
	continue;
	if (fmt == CMIT_FMT_SHORT)
	break;
	} else {
	body = 1;
	}
	memset(buf + offset, ' ', 4);
	memcpy(buf + offset + 4, line, linelen);
	offset += linelen + 4;
	}
	/* Make sure there is an EOLN */
	if (buf[offset - 1] != '\n')
	buf[offset++] = '\n';
	buf[offset] = '\0';
	return offset;
	}

	struct commit pop_commit(struct commit_list *stack)
	{
	struct commit_list top = stack;
	struct commit *item = top ? top->item : NULL;

	if (top) {
	*stack = top->next;
	free(top);
	}
	return item;
	}

	int count_parents(struct commit * commit)
	{
	int count = 0;
	struct commit_list * parents = commit->parents;
	for (count=0;parents; parents=parents->next,count++)
	;
	return count;
	}

	/*
	* Performs an in-place topological sort on the list supplied.
	*/
	void sort_in_topological_order(struct commit_list ** list)
	{
	struct commit_list * next = *list;
	struct commit_list * work = NULL;
	struct commit_list ** pptr = list;
	struct sort_node * nodes;
	struct sort_node * next_nodes;
	int count = 0;

	/* determine the size of the list */
	while (next) {
	next = next->next;
	count++;
	}
	/* allocate an array to help sort the list */
	nodes = xcalloc(count, sizeof(*nodes));
	/* link the list to the array */
	next_nodes = nodes;
	next=*list;
	while (next) {
	next_nodes->list_item = next;
	next->item->object.util = next_nodes;
	next_nodes++;
	next = next->next;
	}
	/* update the indegree */
	next=*list;
	while (next) {
	struct commit_list * parents = next->item->parents;
	while (parents) {
	struct commit * parent=parents->item;
	struct sort_node * pn = (struct sort_node *)parent->object.util;

	if (pn)
	pn->indegree++;
	parents=parents->next;
	}
	next=next->next;
	}
	/*
	* find the tips
	*
	* tips are nodes not reachable from any other node in the list
	*
	* the tips serve as a starting set for the work queue.
	*/
	next=*list;
	while (next) {
	struct sort_node * node = (struct sort_node *)next->item->object.util;

	if (node->indegree == 0) {
	commit_list_insert(next->item, &work);
	}
	next=next->next;
	}
	/* process the list in topological order */
	while (work) {
	struct commit * work_item = pop_commit(&work);
	struct sort_node * work_node = (struct sort_node *)work_item->object.util;
	struct commit_list * parents = work_item->parents;

	while (parents) {
	struct commit * parent=parents->item;
	struct sort_node * pn = (struct sort_node *)parent->object.util;

	if (pn) {
	/*
	* parents are only enqueued for emission
	* when all their children have been emitted thereby
	* guaranteeing topological order.
	*/
	pn->indegree--;
	if (!pn->indegree)
	commit_list_insert(parent, &work);
	}
	parents=parents->next;
	}
	/*
	* work_item is a commit all of whose children
	* have already been emitted. we can emit it now.
	*/
	*pptr = work_node->list_item;
	pptr = &(*pptr)->next;
	*pptr = NULL;
	work_item->object.util = NULL;
	}
	free(nodes);
	}