Add standard interface for file diff functions

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

2 files changed, 86 insertions, 0 deletions

diff --git a/cgit.h b/cgit.h
index 24b02d7..43de375 100644
--- a/cgit.h
+++ b/cgit.h
@@ -1,174 +1,181 @@
 #ifndef CGIT_H
 #define CGIT_H
 
 
 #include <git-compat-util.h>
 #include <cache.h>
 #include <grep.h>
 #include <object.h>
 #include <tree.h>
 #include <commit.h>
 #include <tag.h>
 #include <diff.h>
 #include <diffcore.h>
 #include <refs.h>
 #include <revision.h>
 #include <log-tree.h>
 #include <archive.h>
 #include <xdiff/xdiff.h>
 
 
 typedef void (*configfn)(const char *name, const char *value);
 typedef void (*filepair_fn)(struct diff_filepair *pair);
+typedef void (*linediff_fn)(char *line, int len);
 
 struct cacheitem {
 	char *name;
 	struct stat st;
 	int ttl;
 	int fd;
 };
 
 struct repoinfo {
 	char *url;
 	char *name;
 	char *path;
 	char *desc;
 	char *owner;
 	char *module_link;
 	int snapshots;
 };
 
 struct repolist {
 	int length;
 	int count;
 	struct repoinfo *repos;
 };
 
 struct commitinfo {
 	struct commit *commit;
 	char *author;
 	char *author_email;
 	unsigned long author_date;
 	char *committer;
 	char *committer_email;
 	unsigned long committer_date;
 	char *subject;
 	char *msg;
 };
 
 struct taginfo {
 	char *tagger;
 	char *tagger_email;
 	int tagger_date;
 	char *msg;
 };
 
 extern const char cgit_version[];
 
 extern struct repolist cgit_repolist;
 extern struct repoinfo *cgit_repo;
 
 extern char *cgit_root_title;
 extern char *cgit_css;
 extern char *cgit_logo;
 extern char *cgit_logo_link;
 extern char *cgit_module_link;
 extern char *cgit_virtual_root;
 extern char *cgit_cache_root;
 
 extern int cgit_nocache;
 extern int cgit_snapshots;
 extern int cgit_max_lock_attempts;
 extern int cgit_cache_root_ttl;
 extern int cgit_cache_repo_ttl;
 extern int cgit_cache_dynamic_ttl;
 extern int cgit_cache_static_ttl;
 extern int cgit_cache_max_create_time;
 
 extern int cgit_max_msg_len;
 
 extern char *cgit_repo_name;
 extern char *cgit_repo_desc;
 extern char *cgit_repo_owner;
 
 extern int cgit_query_has_symref;
 extern int cgit_query_has_sha1;
 
 extern char *cgit_querystring;
 extern char *cgit_query_repo;
 extern char *cgit_query_page;
 extern char *cgit_query_search;
 extern char *cgit_query_head;
 extern char *cgit_query_sha1;
 extern char *cgit_query_sha2;
 extern char *cgit_query_path;
 extern char *cgit_query_name;
 extern int   cgit_query_ofs;
 
 extern int htmlfd;
 
 extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
 
 extern int hextoint(char c);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
+
+extern int cgit_diff_files(const unsigned char *old_sha1,
+			   const unsigned char *new_sha1,
+			   linediff_fn fn);
+
 extern void cgit_diff_tree(const unsigned char *old_sha1,
 			   const unsigned char *new_sha1,
 			   filepair_fn fn);
+
 extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
 
 extern char *fmt(const char *format,...);
 
 extern void html(const char *txt);
 extern void htmlf(const char *format,...);
 extern void html_txt(char *txt);
 extern void html_ntxt(int len, char *txt);
 extern void html_attr(char *txt);
 extern void html_hidden(char *name, char *value);
 extern void html_link_open(char *url, char *title, char *class);
 extern void html_link_close(void);
 extern void html_filemode(unsigned short mode);
 
 extern int cgit_read_config(const char *filename, configfn fn);
 extern int cgit_parse_query(char *txt, configfn fn);
 extern struct commitinfo *cgit_parse_commit(struct commit *commit);
 extern struct taginfo *cgit_parse_tag(struct tag *tag);
 
 extern char *cache_safe_filename(const char *unsafe);
 extern int cache_lock(struct cacheitem *item);
 extern int cache_unlock(struct cacheitem *item);
 extern int cache_cancel_lock(struct cacheitem *item);
 extern int cache_exist(struct cacheitem *item);
 extern int cache_expired(struct cacheitem *item);
 
 extern char *cgit_repourl(const char *reponame);
 extern char *cgit_pageurl(const char *reponame, const char *pagename, 
 			  const char *query);
 
 extern void cgit_print_error(char *msg);
 extern void cgit_print_date(unsigned long secs);
 extern void cgit_print_docstart(char *title, struct cacheitem *item);
 extern void cgit_print_docend();
 extern void cgit_print_pageheader(char *title, int show_search);
 extern void cgit_print_snapshot_start(const char *mimetype, 
 				      const char *filename, 
 				      struct cacheitem *item);
 
 extern void cgit_print_repolist(struct cacheitem *item);
 extern void cgit_print_summary();
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep);
 extern void cgit_print_view(const char *hex, char *path);
 extern void cgit_print_blob(struct cacheitem *item, const char *hex, char *path);
 extern void cgit_print_tree(const char *hex, char *path);
 extern void cgit_print_commit(const char *hex);
 extern void cgit_print_diff(const char *old_hex, const char *new_hex);
 extern void cgit_print_snapshot(struct cacheitem *item, const char *hex, 
 				const char *format, const char *prefix,
 				const char *filename);
 
 #endif /* CGIT_H */
diff --git a/shared.c b/shared.c
index f8a17b6..801f68d 100644
--- a/shared.c
+++ b/shared.c
@@ -1,240 +1,319 @@
 /* shared.c: global vars + some callback functions
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 struct repolist cgit_repolist;
 struct repoinfo *cgit_repo;
 
 char *cgit_root_title   = "Git repository browser";
 char *cgit_css          = "/cgit.css";
 char *cgit_logo         = "/git-logo.png";
 char *cgit_logo_link    = "http://www.kernel.org/pub/software/scm/git/docs/";
 char *cgit_module_link  = "./?repo=%s&page=commit&id=%s";
 char *cgit_virtual_root = NULL;
 
 char *cgit_cache_root   = "/var/cache/cgit";
 
 int cgit_nocache               =  0;
 int cgit_snapshots             =  0;
 int cgit_max_lock_attempts     =  5;
 int cgit_cache_root_ttl        =  5;
 int cgit_cache_repo_ttl        =  5;
 int cgit_cache_dynamic_ttl     =  5;
 int cgit_cache_static_ttl      = -1;
 int cgit_cache_max_create_time =  5;
 
 int cgit_max_msg_len = 60;
 
 char *cgit_repo_name    = NULL;
 char *cgit_repo_desc    = NULL;
 char *cgit_repo_owner   = NULL;
 
 int cgit_query_has_symref = 0;
 int cgit_query_has_sha1   = 0;
 
 char *cgit_querystring  = NULL;
 char *cgit_query_repo   = NULL;
 char *cgit_query_page   = NULL;
 char *cgit_query_head   = NULL;
 char *cgit_query_search = NULL;
 char *cgit_query_sha1   = NULL;
 char *cgit_query_sha2   = NULL;
 char *cgit_query_path   = NULL;
 char *cgit_query_name   = NULL;
 int   cgit_query_ofs    = 0;
 
 int htmlfd = 0;
 
 int chk_zero(int result, char *msg)
 {
 	if (result != 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
 }
 
 int chk_positive(int result, char *msg)
 {
 	if (result <= 0)
 		die("%s: %s", msg, strerror(errno));
 	return result;
 }
 
 struct repoinfo *add_repo(const char *url)
 {
 	struct repoinfo *ret;
 
 	if (++cgit_repolist.count > cgit_repolist.length) {
 		if (cgit_repolist.length == 0)
 			cgit_repolist.length = 8;
 		else
 			cgit_repolist.length *= 2;
 		cgit_repolist.repos = xrealloc(cgit_repolist.repos,
 					       cgit_repolist.length *
 					       sizeof(struct repoinfo));
 	}
 
 	ret = &cgit_repolist.repos[cgit_repolist.count-1];
 	ret->url = xstrdup(url);
 	ret->name = ret->url;
 	ret->path = NULL;
 	ret->desc = NULL;
 	ret->owner = NULL;
 	ret->snapshots = cgit_snapshots;
 	ret->module_link = cgit_module_link;
 	return ret;
 }
 
 void cgit_global_config_cb(const char *name, const char *value)
 {
 	if (!strcmp(name, "root-title"))
 		cgit_root_title = xstrdup(value);
 	else if (!strcmp(name, "css"))
 		cgit_css = xstrdup(value);
 	else if (!strcmp(name, "logo"))
 		cgit_logo = xstrdup(value);
 	else if (!strcmp(name, "logo-link"))
 		cgit_logo_link = xstrdup(value);
 	else if (!strcmp(name, "module-link"))
 		cgit_module_link = xstrdup(value);
 	else if (!strcmp(name, "virtual-root"))
 		cgit_virtual_root = xstrdup(value);
 	else if (!strcmp(name, "nocache"))
 		cgit_nocache = atoi(value);
 	else if (!strcmp(name, "snapshots"))
 		cgit_snapshots = atoi(value);
 	else if (!strcmp(name, "cache-root"))
 		cgit_cache_root = xstrdup(value);
 	else if (!strcmp(name, "cache-root-ttl"))
 		cgit_cache_root_ttl = atoi(value);
 	else if (!strcmp(name, "cache-repo-ttl"))
 		cgit_cache_repo_ttl = atoi(value);
 	else if (!strcmp(name, "cache-static-ttl"))
 		cgit_cache_static_ttl = atoi(value);
 	else if (!strcmp(name, "cache-dynamic-ttl"))
 		cgit_cache_dynamic_ttl = atoi(value);
 	else if (!strcmp(name, "max-message-length"))
 		cgit_max_msg_len = atoi(value);
 	else if (!strcmp(name, "repo.url"))
 		cgit_repo = add_repo(value);
 	else if (!strcmp(name, "repo.name"))
 		cgit_repo->name = xstrdup(value);
 	else if (cgit_repo && !strcmp(name, "repo.path"))
 		cgit_repo->path = xstrdup(value);
 	else if (cgit_repo && !strcmp(name, "repo.desc"))
 		cgit_repo->desc = xstrdup(value);
 	else if (cgit_repo && !strcmp(name, "repo.owner"))
 		cgit_repo->owner = xstrdup(value);
 	else if (cgit_repo && !strcmp(name, "repo.snapshots"))
 		cgit_repo->snapshots = atoi(value);
 	else if (cgit_repo && !strcmp(name, "repo.module-link"))
 		cgit_repo->module_link= xstrdup(value);
 }
 
 void cgit_repo_config_cb(const char *name, const char *value)
 {
 	if (!strcmp(name, "name"))
 		cgit_repo_name = xstrdup(value);
 	else if (!strcmp(name, "desc"))
 		cgit_repo_desc = xstrdup(value);
 	else if (!strcmp(name, "owner"))
 		cgit_repo_owner = xstrdup(value);
 }
 
 void cgit_querystring_cb(const char *name, const char *value)
 {
 	if (!strcmp(name,"r")) {
 		cgit_query_repo = xstrdup(value);
 	} else if (!strcmp(name, "p")) {
 		cgit_query_page = xstrdup(value);
 	} else if (!strcmp(name, "q")) {
 		cgit_query_search = xstrdup(value);
 	} else if (!strcmp(name, "h")) {
 		cgit_query_head = xstrdup(value);
 		cgit_query_has_symref = 1;
 	} else if (!strcmp(name, "id")) {
 		cgit_query_sha1 = xstrdup(value);
 		cgit_query_has_sha1 = 1;
 	} else if (!strcmp(name, "id2")) {
 		cgit_query_sha2 = xstrdup(value);
 		cgit_query_has_sha1 = 1;
 	} else if (!strcmp(name, "ofs")) {
 		cgit_query_ofs = atoi(value);
 	} else if (!strcmp(name, "path")) {
 		cgit_query_path = xstrdup(value);
 	} else if (!strcmp(name, "name")) {
 		cgit_query_name = xstrdup(value);
 	}
 }
 
 void *cgit_free_commitinfo(struct commitinfo *info)
 {
 	free(info->author);
 	free(info->author_email);
 	free(info->committer);
 	free(info->committer_email);
 	free(info->subject);
 	free(info);
 	return NULL;
 }
 
 int hextoint(char c)
 {
 	if (c >= 'a' && c <= 'f')
 		return 10 + c - 'a';
 	else if (c >= 'A' && c <= 'F')
 		return 10 + c - 'A';
 	else if (c >= '0' && c <= '9')
 		return c - '0';
 	else
 		return -1;
 }
 
 void cgit_diff_tree_cb(struct diff_queue_struct *q,
 		       struct diff_options *options, void *data)
 {
 	int i;
 
 	for (i = 0; i < q->nr; i++) {
 		if (q->queue[i]->status == 'U')
 			continue;
 		((filepair_fn)data)(q->queue[i]);
 	}
 }
 
+static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
+{
+	enum object_type type;
+
+	if (is_null_sha1(sha1)) {
+		file->ptr = (char *)"";
+		file->size = 0;
+	} else {
+		file->ptr = read_sha1_file(sha1, &type, &file->size);
+	}
+	return 1;
+}
+
+/*
+ * Receive diff-buffers from xdiff and concatenate them as
+ * needed across multiple callbacks.
+ *
+ * This is basically a copy of xdiff-interface.c/xdiff_outf(),
+ * ripped from git and modified to use globals instead of
+ * a special callback-struct.
+ */
+char *diffbuf = NULL;
+int buflen = 0;
+
+int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
+{
+	int i;
+
+	for (i = 0; i < nbuf; i++) {
+		if (mb[i].ptr[mb[i].size-1] != '\n') {
+			/* Incomplete line */
+			diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
+			memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
+			buflen += mb[i].size;
+			continue;
+		}
+
+		/* we have a complete line */
+		if (!diffbuf) {
+			((linediff_fn)priv)(mb[i].ptr, mb[i].size);
+			continue;
+		}
+		diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
+		memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
+		((linediff_fn)priv)(diffbuf, buflen + mb[i].size);
+		free(diffbuf);
+		diffbuf = NULL;
+		buflen = 0;
+	}
+	if (diffbuf) {
+		((linediff_fn)priv)(diffbuf, buflen);
+		free(diffbuf);
+		diffbuf = NULL;
+		buflen = 0;
+	}
+	return 0;
+}
+
+int cgit_diff_files(const unsigned char *old_sha1,
+		     const unsigned char *new_sha1,
+		     linediff_fn fn)
+{
+	mmfile_t file1, file2;
+	xpparam_t diff_params;
+	xdemitconf_t emit_params;
+	xdemitcb_t emit_cb;
+
+	if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
+		return 1;
+
+	diff_params.flags = XDF_NEED_MINIMAL;
+	emit_params.ctxlen = 3;
+	emit_params.flags = XDL_EMIT_FUNCNAMES;
+	emit_cb.outf = filediff_cb;
+	emit_cb.priv = fn;
+	xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
+	return 0;
+}
+
 void cgit_diff_tree(const unsigned char *old_sha1,
 		    const unsigned char *new_sha1,
 		    filepair_fn fn)
 {
 	struct diff_options opt;
 	int ret;
 
 	diff_setup(&opt);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.detect_rename = 1;
 	opt.recursive = 1;
 	opt.format_callback = cgit_diff_tree_cb;
 	opt.format_callback_data = fn;
 	diff_setup_done(&opt);
 
 	if (old_sha1)
 		ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
 	else
 		ret = diff_root_tree_sha1(new_sha1, "", &opt);
 	diffcore_std(&opt);
 	diff_flush(&opt);
 }
 
 void cgit_diff_commit(struct commit *commit, filepair_fn fn)
 {
 	unsigned char *old_sha1 = NULL;
 
 	if (commit->parents)
 		old_sha1 = commit->parents->item->object.sha1;
 	cgit_diff_tree(old_sha1, commit->object.sha1, fn);
 }