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-rw-r--r--.gitignore1
-rw-r--r--Makefile6
-rw-r--r--README54
-rw-r--r--cache.c86
-rw-r--r--cgit.c117
-rw-r--r--cgit.h47
-rw-r--r--config.c4
-rw-r--r--git.h60
-rw-r--r--html.c6
9 files changed, 353 insertions, 28 deletions
diff --git a/.gitignore b/.gitignore
index 4eaec97..c4c9ac3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 # Files I don't care to see in git-status/commit
 cgit
 *.o
+*~
diff --git a/Makefile b/Makefile
index 4e72b07..243f590 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,9 @@ INSTALL_BIN = /var/www/htdocs/cgit.cgi
 INSTALL_CSS = /var/www/htdocs/cgit.css
 
 EXTLIBS = ../git/libgit.a ../git/xdiff/lib.a -lz -lcrypto
-OBJECTS = cgit.o config.o html.o
+OBJECTS = cgit.o config.o html.o cache.o
+
+CFLAGS += -Wall
 
 all: cgit
 
@@ -15,6 +17,6 @@ clean:
 	rm -f cgit *.o
 
 cgit: $(OBJECTS)
-	$(CC) -o cgit $(OBJECTS) $(EXTLIBS)
+	$(CC) $(CFLAGS) -o cgit $(OBJECTS) $(EXTLIBS)
 
 $(OBJECTS): cgit.h git.h
diff --git a/README b/README
new file mode 100644
index 0000000..5917c37
--- /dev/null
+++ b/README
@@ -0,0 +1,54 @@
+Cache algorithm
+===============
+
+Cgit normally returns cached pages when invoked. If there is no cache file, or
+the cache file has expired, it is regenerated. Finally, the cache file is 
+printed on stdout.
+
+When it is decided that a cache file needs to be regenerated, an attempt is 
+made to create a corresponding lockfile. If this fails, the process gives up
+and uses the expired cache file instead.
+
+When there is no cache file for a request, an attempt is made to create a 
+corresponding lockfile. If this fails, the process calls sched_yield(2) before
+restarting the request handling.
+
+In pseudocode:
+
+	name = generate_cache_name(request);
+top:
+	if (!exists(name)) {
+		if (lock_cache(name)) {
+			generate_cache(request, name);
+			unlock_cache(name);
+		} else {
+			sched_yield();
+			goto top;
+		}
+	} else if (expired(name)) {
+		if (lock_cache(name)) {
+			generate_cache(request, name);
+			unlock_cache(name);
+		}
+	}
+	print_file(name);
+
+
+The following options can be set in /etc/cgitrc to control cache behaviour:
+  cache-root:        root directory for cache files
+  cache-root-ttl:    TTL for the repo listing page
+  cache-repo-ttl:    TTL for any repos summary page
+  cache-dynamic-ttl: TTL for pages with symbolic references (not SHA1)
+  cache-static-ttl:  TTL for pages with sha1 references
+
+TTL is specified in minutes, -1 meaning "infinite caching". 
+
+
+Naming of cache files
+---------------------
+Repository listing:  <cachedir>/index.html
+Repository summary:  <cachedir>/<repo>/index.html
+Repository subpage:  <cachedir>/<repo>/<page>/<querystring>.html
+
+The corresponding lock files have a ".lock" suffix.
+
diff --git a/cache.c b/cache.c
new file mode 100644
index 0000000..1be1ea4
--- /dev/null
+++ b/cache.c
@@ -0,0 +1,86 @@
+#include "cgit.h"
+
+const int NOLOCK = -1;
+
+int cache_lookup(struct cacheitem *item)
+{
+	if (!cgit_query_repo) {
+		item->name = xstrdup(fmt("%s/index.html", cgit_cache_root));
+		item->ttl = cgit_cache_root_ttl;
+	} else if (!cgit_query_page) {
+		item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root, 
+			   cgit_query_repo));
+		item->ttl = cgit_cache_repo_ttl;
+	} else {
+		item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root, 
+			   cgit_query_repo, cgit_query_page, 
+			   cgit_querystring));
+		if (cgit_query_has_symref)
+			item->ttl = cgit_cache_dynamic_ttl;
+		else if (cgit_query_has_sha1)
+			item->ttl = cgit_cache_static_ttl;
+		else
+			item->ttl = cgit_cache_repo_ttl;
+	}
+	if (stat(item->name, &item->st)) {
+		item->st.st_mtime = 0;
+		return 0;
+	}
+	return 1;
+}
+
+int cache_create_dirs()
+{
+	char *path;
+
+	if (!cgit_query_repo)
+		return 0;
+
+	path = fmt("%s/%s", cgit_cache_root, cgit_query_repo);
+	if (mkdir(path, S_IRWXU) && errno!=EEXIST)
+		return 0;
+
+	if (cgit_query_page) {
+		path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo, 
+			   cgit_query_page);
+		if (mkdir(path, S_IRWXU) && errno!=EEXIST)
+			return 0;
+	}
+	return 1;
+}
+
+int cache_lock(struct cacheitem *item)
+{
+	int ret;
+	char *lockfile = fmt("%s.lock", item->name);
+
+ top:  
+       	item->fd = open(lockfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR|S_IWUSR);
+	if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())
+		goto top;
+	if (item->fd == NOLOCK && errno == EEXIST) {
+		struct stat st;
+		time_t t;
+		if (stat(lockfile, &st))
+			return ret;
+		t = time(NULL);
+		if (t-st.st_mtime > cgit_cache_max_create_time && 
+		    !unlink(lockfile))
+			goto top;
+		return 0;
+	}
+	return (item->fd > 0);
+}
+
+int cache_unlock(struct cacheitem *item)
+{
+	close(item->fd);
+	return (rename(fmt("%s.lock", item->name), item->name) == 0);
+}
+
+int cache_expired(struct cacheitem *item)
+{
+	if (item->ttl < 0)
+		return 0;
+	return item->st.st_mtime + item->ttl * 60 < time(NULL);
+}
diff --git a/cgit.c b/cgit.c
index 4c14f77..09c857c 100644
--- a/cgit.c
+++ b/cgit.c
@@ -10,29 +10,47 @@ static const char cgit_error[] =
 static const char cgit_lib_error[] =
 "<div class='error'>%s: %s</div>";
 
+int htmlfd = 0;
 
-char *cgit_root         = "/var/git";
+char *cgit_root         = "/usr/src/git";
 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_virtual_root = NULL;
 
+char *cgit_cache_root   = "/var/cache/cgit";
+
+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;
+
 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_sha1   = NULL;
+
+struct cacheitem cacheitem;
 
 int cgit_parse_query(char *txt, configfn fn)
 {
-	char *t = txt, *value = NULL, c;
+	char *t, *value = NULL, c;
 
 	if (!txt)
 		return 0;
 
+	t = txt = xstrdup(txt);
+ 
 	while((c=*t) != '\0') {
 		if (c=='=') {
 			*t = '\0';
@@ -82,8 +100,13 @@ void cgit_querystring_cb(const char *name, const char *value)
 		cgit_query_repo = xstrdup(value);
 	else if (!strcmp(name, "p"))
 		cgit_query_page = xstrdup(value);
-	else if (!strcmp(name, "h"))
+	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;
+	}
 }
 
 char *cgit_repourl(const char *reponame)
@@ -136,9 +159,32 @@ static int cgit_print_branch_cb(const char *refname, const unsigned char *sha1,
 	return 0;
 }
 
+/* Sun, 06 Nov 1994 08:49:37 GMT */
+static char *http_date(time_t t)
+{
+	static char day[][4] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
+	static char month[][4] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+				  "Jul", "Aug", "Sep", "Oct", "Now", "Dec"};
+	struct tm *tm = gmtime(&t);
+	return fmt("%s, %02d %s %04d %02d:%02d:%02d GMT", day[tm->tm_wday],
+		   tm->tm_mday, month[tm->tm_mon], 1900+tm->tm_year,
+		   tm->tm_hour, tm->tm_min, tm->tm_sec);
+}
+
+static int ttl_seconds(int ttl)
+{
+	if (ttl<0)
+		return 60 * 60 * 24 * 365;
+	else 
+		return ttl * 60;
+}
+
 static void cgit_print_docstart(char *title)
 {
 	html("Content-Type: text/html; charset=utf-8\n");
+	htmlf("Last-Modified: %s\n", http_date(cacheitem.st.st_mtime));
+	htmlf("Expires: %s\n", http_date(cacheitem.st.st_mtime + 
+					 ttl_seconds(cacheitem.ttl)));
 	html("\n");
 	html(cgit_doctype);
 	html("<html>\n");
@@ -175,6 +221,7 @@ static void cgit_print_repolist()
 	struct stat st;
 	char *name;
 
+	chdir(cgit_root);
 	cgit_print_docstart(cgit_root_title);
 	cgit_print_pageheader(cgit_root_title);
 
@@ -197,7 +244,7 @@ static void cgit_print_repolist()
 			continue;
 
 		cgit_repo_name = cgit_repo_desc = cgit_repo_owner = NULL;
-		name = fmt("%s/.git/info/cgit", de->d_name);
+		name = fmt("%s/info/cgit", de->d_name);
 		if (cgit_read_config(name, cgit_repo_config_cb))
 			continue;
 
@@ -291,7 +338,7 @@ static void cgit_print_commit_shortlog(struct commit *commit)
 	strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", time);
 	html_txt(buf);
 	html("</td><td>");
-	char *qry = fmt("h=%s", sha1_to_hex(commit->object.sha1));
+	char *qry = fmt("id=%s", sha1_to_hex(commit->object.sha1));
 	char *url = cgit_pageurl(cgit_query_repo, "view", qry);
 	html_link_open(url, NULL, NULL);
 	html_txt(subject);
@@ -371,8 +418,8 @@ static void cgit_print_object(char *hex)
 
 static void cgit_print_repo_page()
 {
-	if (chdir(cgit_query_repo) || 
-	    cgit_read_config(".git/info/cgit", cgit_repo_config_cb)) {
+	if (chdir(fmt("%s/%s", cgit_root, cgit_query_repo)) || 
+	    cgit_read_config("info/cgit", cgit_repo_config_cb)) {
 		char *title = fmt("%s - %s", cgit_root_title, "Bad request");
 		cgit_print_docstart(title);
 		cgit_print_pageheader(title);
@@ -381,7 +428,7 @@ static void cgit_print_repo_page()
 		cgit_print_docend();
 		return;
 	}
-	
+	setenv("GIT_DIR", fmt("%s/%s", cgit_root, cgit_query_repo), 1);
 	char *title = fmt("%s - %s", cgit_repo_name, cgit_repo_desc);
 	cgit_print_docstart(title);
 	cgit_print_pageheader(title);
@@ -390,21 +437,61 @@ static void cgit_print_repo_page()
 	else if (!strcmp(cgit_query_page, "log")) {
 		cgit_print_log(cgit_query_head, 0, 100);
 	} else if (!strcmp(cgit_query_page, "view")) {
-		cgit_print_object(cgit_query_head);
+		cgit_print_object(cgit_query_sha1);
 	}
 	cgit_print_docend();
 }
 
-int main(int argc, const char **argv)
+static void cgit_fill_cache(struct cacheitem *item)
 {
-	if (cgit_read_config("/etc/cgitrc", cgit_global_config_cb))
-		die("Error reading config: %d %s", errno, strerror(errno));
-
-	chdir(cgit_root);
-	cgit_parse_query(getenv("QUERY_STRING"), cgit_querystring_cb);
+	htmlfd = item->fd;
+	item->st.st_mtime = time(NULL);
 	if (cgit_query_repo)
 		cgit_print_repo_page();
 	else
 		cgit_print_repolist();
+}
+
+static void cgit_refresh_cache(struct cacheitem *item)
+{
+ top:
+	if (!cache_lookup(item)) {
+		if (cache_lock(item)) {
+			cgit_fill_cache(item);
+			cache_unlock(item);
+		} else {
+			sched_yield();
+			goto top;
+		}
+	} else if (cache_expired(item)) {
+		if (cache_lock(item)) {
+			cgit_fill_cache(item);
+			cache_unlock(item);
+		}
+	}
+}
+
+static void cgit_print_cache(struct cacheitem *item)
+{
+	static char buf[4096];
+	ssize_t i;
+
+	int fd = open(item->name, O_RDONLY);
+	if (fd<0)
+		die("Unable to open cached file %s", item->name);
+
+	while((i=read(fd, buf, sizeof(buf))) > 0)
+		write(STDOUT_FILENO, buf, i);
+
+	close(fd);
+}
+
+int main(int argc, const char **argv)
+{
+	cgit_read_config("/etc/cgitrc", cgit_global_config_cb);
+	cgit_querystring = xstrdup(getenv("QUERY_STRING"));
+	cgit_parse_query(cgit_querystring, cgit_querystring_cb);
+	cgit_refresh_cache(&cacheitem);
+	cgit_print_cache(&cacheitem);
 	return 0;
 }
diff --git a/cgit.h b/cgit.h
index 19f7ba7..1e084d4 100644
--- a/cgit.h
+++ b/cgit.h
@@ -3,6 +3,46 @@
 
 #include "git.h"
 #include <openssl/sha.h>
+#include <ctype.h>
+#include <sched.h>
+
+typedef void (*configfn)(const char *name, const char *value);
+
+struct cacheitem {
+	char *name;
+	struct stat st;
+	int ttl;
+	int fd;
+};
+
+extern char *cgit_root;
+extern char *cgit_root_title;
+extern char *cgit_css;
+extern char *cgit_logo;
+extern char *cgit_logo_link;
+extern char *cgit_virtual_root;
+extern char *cgit_cache_root;
+
+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 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_head;
+extern char *cgit_query_sha1;
+
+extern int htmlfd;
 
 extern char *fmt(const char *format,...);
 
@@ -10,12 +50,15 @@ extern void html(const char *txt);
 extern void htmlf(const char *format,...);
 extern void html_txt(char *txt);
 extern void html_attr(char *txt);
-
 extern void html_link_open(char *url, char *title, char *class);
 extern void html_link_close(void);
 
-typedef void (*configfn)(const char *name, const char *value);
 
 extern int cgit_read_config(const char *filename, configfn fn);
 
+extern int cache_lookup(struct cacheitem *item);
+extern int cache_lock(struct cacheitem *item);
+extern int cache_unlock(struct cacheitem *item);
+extern int cache_expired(struct cacheitem *item);
+
 #endif /* CGIT_H */
diff --git a/config.c b/config.c
index 858ab69..ee49b62 100644
--- a/config.c
+++ b/config.c
@@ -32,7 +32,7 @@ int read_config_line(FILE *f, char *line, const char **value, int bufsize)
 			skip_line(f);
 			continue;
 		}
-		if (!isname && isblank(c))
+		if (!isname && isspace(c))
 			continue;
 
 		if (c=='=' && !*value) {
@@ -64,7 +64,7 @@ int cgit_read_config(const char *filename, configfn fn)
 	if (!f)
 		return -1;
 
-	while(len = read_config_line(f, line, &value, sizeof(line)))
+	while((len = read_config_line(f, line, &value, sizeof(line))) > 0)
 		(*fn)(line, value);
 
 	fclose(f);
diff --git a/git.h b/git.h
index 443f216..dfa3542 100644
--- a/git.h
+++ b/git.h
@@ -33,6 +33,26 @@
 #include <time.h>
 
 
+/* On most systems <limits.h> would have given us this, but
+ * not on some systems (e.g. GNU/Hurd).
+ */
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+#ifdef __GNUC__
+#define NORETURN __attribute__((__noreturn__))
+#else
+#define NORETURN
+#ifndef __attribute__
+#define __attribute__(x)
+#endif
+#endif
+
+
+extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
+
+
 static inline char* xstrdup(const char *str)
 {
 	char *ret = strdup(str);
@@ -108,9 +128,13 @@ static inline ssize_t xwrite(int fd, const void *buf, size_t len)
 #define MINIMUM_ABBREV 4
 #define DEFAULT_ABBREV 7
 
+extern int sha1_object_info(const unsigned char *, char *, unsigned long *);
 
 extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size);
 
+extern int get_sha1(const char *str, unsigned char *sha1);
+extern int get_sha1_hex(const char *hex, unsigned char *sha1);
+extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
 
 
 
@@ -183,6 +207,21 @@ struct commit {
 };
 
 
+struct commit *lookup_commit(const unsigned char *sha1);
+struct commit *lookup_commit_reference(const unsigned char *sha1);
+struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
+					      int quiet);
+
+int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size);
+int parse_commit(struct commit *item);
+
+struct commit_list * commit_list_insert(struct commit *item, struct commit_list **list_p);
+struct commit_list * insert_by_date(struct commit *item, struct commit_list **list);
+
+void free_commit_list(struct commit_list *list);
+
+void sort_by_date(struct commit_list **list);
+
 /* Commit formats */
 enum cmit_fmt {
 	CMIT_FMT_RAW,
@@ -197,13 +236,9 @@ enum cmit_fmt {
 	CMIT_FMT_UNSPECIFIED,
 };
 
+extern unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *, unsigned long len, char *buf, unsigned long space, int abbrev, const char *subject, const char *after_subject, int relative_date);
 
 
-struct commit *lookup_commit(const unsigned char *sha1);
-struct commit *lookup_commit_reference(const unsigned char *sha1);
-struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
-					      int quiet);
-
 typedef void (*topo_sort_set_fn_t)(struct commit*, void *data);
 typedef void* (*topo_sort_get_fn_t)(struct commit*);
 
@@ -306,6 +341,16 @@ enum color_diff {
 
 
 
+/*
+ * from git:refs.g
+ */
+
+typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data);
+extern int head_ref(each_ref_fn, void *);
+extern int for_each_ref(each_ref_fn, void *);
+extern int for_each_tag_ref(each_ref_fn, void *);
+extern int for_each_branch_ref(each_ref_fn, void *);
+extern int for_each_remote_ref(each_ref_fn, void *);
 
 
 
@@ -391,6 +436,11 @@ struct rev_info {
 };
 
 
+extern void init_revisions(struct rev_info *revs, const char *prefix);
+extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
+extern int handle_revision_arg(const char *arg, struct rev_info *revs,int flags,int cant_be_filename);
+
+extern void prepare_revision_walk(struct rev_info *revs);
 extern struct commit *get_revision(struct rev_info *revs);
 
 
diff --git a/html.c b/html.c
index 5780dc1..bf1490f 100644
--- a/html.c
+++ b/html.c
@@ -20,16 +20,18 @@ char *fmt(const char *format, ...)
 
 void html(const char *txt)
 {
-	fputs(txt, stdout);
+	write(htmlfd, txt, strlen(txt));
 }
 
 void htmlf(const char *format, ...)
 {
+	static char buf[65536];
 	va_list args;
 
 	va_start(args, format);
-	vprintf(format, args);
+	vsnprintf(buf, sizeof(buf), format, args);
 	va_end(args);
+	html(buf);
 }
 
 void html_txt(char *txt)