Add caching infrastructure

This enables internal caching of page output. Page requests are split into four groups: 1) repo listing (front page) 2) repo summary 3) repo pages w/symbolic references in query string 4) repo pages w/constant sha1's in query string Each group has a TTL specified in minutes. When a page is requested, a cached filename is stat(2)'ed and st_mtime is compared to time(2). If TTL has expired (or the file didn't exist), the cached file is regenerated. When generating a cached file, locking is used to avoid parallell processing of the request. If multiple processes tries to aquire the same lock, the ones who fail to get the lock serves the (expired) cached file. If the cached file don't exist, the process instead calls sched_yield(2) before restarting the request processing. Signed-off-by: Lars Hjemli <hjemli@gmail.com>
author: Lars Hjemli <hjemli@gmail.com> 2006-12-10 21:31:36 (UTC)
committer: Lars Hjemli <hjemli@gmail.com> 2006-12-10 21:31:36 (UTC)
commit: 25105d7ecaba474d4b7c364ebb586aac3dfc5abb (patch) (unidiff)
tree: 8beb08db1399b8efb8c7fbcd936044ae7fc232e6 /cgit.c
parent: 856c026e221d8ed82c5b75bc8da4bd65e89ea953 (diff)
download: cgit-25105d7ecaba474d4b7c364ebb586aac3dfc5abb.zip
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cgit-25105d7ecaba474d4b7c364ebb586aac3dfc5abb.tar.bz2
1 files changed, 102 insertions, 15 deletions
diff --git a/cgit.c b/cgit.c
index 4c14f77..09c857c 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1,410 +1,497 @@
 #include "cgit.h"
 static const char cgit_doctype[] =
 "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\"\n"
 "  \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";
 static const char cgit_error[] =
 "<div class='error'>%s</div>";
 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';
                        value = t+1;
                } else if (c=='&') {
                        *t = '\0';
                        (*fn)(txt, value);
                        txt = t+1;
                        value = NULL;
                }
                t++;
        }
        if (t!=txt)
                (*fn)(txt, value);
        return 0;
 }
 void cgit_global_config_cb(const char *name, const char *value)
 {
        if (!strcmp(name, "root"))
                cgit_root = xstrdup(value);
        else 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, "virtual-root"))
                cgit_virtual_root = 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, "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)
 {
        if (cgit_virtual_root) {
                return fmt("%s/%s/", cgit_virtual_root, reponame);
        } else {
                return fmt("?r=%s", reponame);
        }
 }
 char *cgit_pageurl(const char *reponame, const char *pagename, 
                   const char *query)
 {
        if (cgit_virtual_root) {
                return fmt("%s/%s/%s/?%s", cgit_virtual_root, reponame, 
                           pagename, query);
        } else {
                return fmt("?r=%s&p=%s&%s", reponame, pagename, query);
        }
 }
 static int cgit_print_branch_cb(const char *refname, const unsigned char *sha1,
                                int flags, void *cb_data)
 {
        struct commit *commit;
        char buf[256], *url;
        commit = lookup_commit(sha1);
        if (commit && !parse_commit(commit)){
                html("<tr><td>");
                url = cgit_pageurl(cgit_query_repo, "log", 
                                   fmt("h=%s", refname));
                html_link_open(url, NULL, NULL);
                strncpy(buf, refname, sizeof(buf));
                html_txt(buf);
                html_link_close();
                html("</td><td>");
                pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0, buf,
                                    sizeof(buf), 0, NULL, NULL, 0);
                html_txt(buf);
                html("</td></tr>\n");
        } else {
                html("<tr><td>");
                html_txt(buf);
                html("</td><td>");
                htmlf("*** bad ref %s", sha1_to_hex(sha1));
                html("</td></tr>\n");
        }
        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");
        html("<head>\n");
        html("<title>");
        html_txt(title);
        html("</title>\n");
        html("<link rel='stylesheet' type='text/css' href='");
        html_attr(cgit_css);
        html("'/>\n");
        html("</head>\n");
        html("<body>\n");
 }
 static void cgit_print_docend()
 {
        html("</body>\n</html>\n");
 }
 static void cgit_print_pageheader(char *title)
 {
        html("<div id='header'>");
        htmlf("<a href='%s'>", cgit_logo_link);
        htmlf("<img id='logo' src='%s'/>\n", cgit_logo);
        htmlf("</a>");
        html_txt(title);
        html("</div>");
 }
 static void cgit_print_repolist()
 {
        DIR *d;
        struct dirent *de;
        struct stat st;
        char *name;
+        chdir(cgit_root);
        cgit_print_docstart(cgit_root_title);
        cgit_print_pageheader(cgit_root_title);
        if (!(d = opendir("."))) {
                htmlf(cgit_lib_error, "Unable to scan repository directory",
                      strerror(errno));
                cgit_print_docend();
                return;
        }
        html("<h2>Repositories</h2>\n");
        html("<table class='list'>");
        html("<tr><th>Name</th><th>Description</th><th>Owner</th></tr>\n");
        while ((de = readdir(d)) != NULL) {
                if (de->d_name[0] == '.')
                        continue;
                if (stat(de->d_name, &st) < 0)
                        continue;
                if (!S_ISDIR(st.st_mode))
                        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;
                html("<tr><td>");
                html_link_open(cgit_repourl(de->d_name), NULL, NULL);
                html_txt(cgit_repo_name);
                html_link_close();
                html("</td><td>");
                html_txt(cgit_repo_desc);
                html("</td><td>");
                html_txt(cgit_repo_owner);
                html("</td></tr>\n");
        }
        closedir(d);
        html("</table>");
        cgit_print_docend();
 }
 static void cgit_print_branches()
 {
        html("<table class='list'>");
        html("<tr><th>Branch name</th><th>Head commit</th></tr>\n");
        for_each_branch_ref(cgit_print_branch_cb, NULL);
        html("</table>");
 }
 static int get_one_line(char *txt)
 {
        char *t;
        for(t=txt; *t != '\n' && t != '\0'; t++)
                ;
        *t = '\0';
        return t-txt-1;
 }
 static void cgit_print_commit_shortlog(struct commit *commit)
 {
        char *h, *t, *p; 
        char *tree = NULL, *author = NULL, *subject = NULL;
        int len;
        time_t sec;
        struct tm *time;
        char buf[32];
        h = t = commit->buffer;
        
        if (strncmp(h, "tree ", 5))
                die("Bad commit format: %s", 
                    sha1_to_hex(commit->object.sha1));
        
        len = get_one_line(h);
        tree = h+5;
        h += len + 2;
        while (!strncmp(h, "parent ", 7))
                h += get_one_line(h) + 2;
        
        if (!strncmp(h, "author ", 7)) {
                author = h+7;
                h += get_one_line(h) + 2;
                t = author;
                while(t!=h && *t!='<') 
                        t++;
                *t='\0';
                p = t;
                while(--t!=author && *t==' ')
                        *t='\0';
                while(++p!=h && *p!='>')
                        ;
                while(++p!=h && !isdigit(*p))
                        ;
                t = p;
                while(++p && isdigit(*p))
                        ;
                *p = '\0';
                sec = atoi(t);
                time = gmtime(&sec);
        }
        while((len = get_one_line(h)) > 0)
                h += len+2;
        h++;
        len = get_one_line(h);
        subject = h;
        html("<tr><td>");
        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);
        html_link_close();
        html("</td><td>");
        html_txt(author);
        html("</td></tr>\n");
 }
 static void cgit_print_log(const char *tip, int ofs, int cnt)
 {
        struct rev_info rev;
        struct commit *commit;
        const char *argv[2] = {NULL, tip};
        int n = 0;
        
        init_revisions(&rev, NULL);
        rev.abbrev = DEFAULT_ABBREV;
        rev.commit_format = CMIT_FMT_DEFAULT;
        rev.verbose_header = 1;
        rev.show_root_diff = 0;
        setup_revisions(2, argv, &rev, NULL);
        prepare_revision_walk(&rev);
        html("<h2>Log</h2>");
        html("<table class='list'>");
        html("<tr><th>Date</th><th>Message</th><th>Author</th></tr>\n");
        while ((commit = get_revision(&rev)) != NULL && n++ < 100) {
                cgit_print_commit_shortlog(commit);
                free(commit->buffer);
                commit->buffer = NULL;
                free_commit_list(commit->parents);
                commit->parents = NULL;
        }
        html("</table>\n");
 }
 static void cgit_print_repo_summary()
 {
        html("<h2>");
        html_txt("Repo summary page");
        html("</h2>");
        cgit_print_branches();
 }
 static void cgit_print_object(char *hex)
 {
        unsigned char sha1[20];
        //struct object *object;
        char type[20];
        unsigned char *buf;
        unsigned long size;
        if (get_sha1_hex(hex, sha1)){
                htmlf(cgit_error, "Bad hex value");
                return;
        }
        if (sha1_object_info(sha1, type, NULL)){
                htmlf(cgit_error, "Bad object name");
                return;
        }
        buf = read_sha1_file(sha1, type, &size);
        if (!buf) {
                htmlf(cgit_error, "Error reading object");
                return;
        }
        buf[size] = '\0';
        html("<h2>Object view</h2>");
        htmlf("sha1=%s<br/>type=%s<br/>size=%i<br/>", hex, type, size);
        html("<pre>");
        html_txt(buf);
        html("</pre>");
 }
 static void cgit_print_repo_page()
 {
-        if (chdir(cgit_query_repo) || 
+        if (chdir(fmt("%s/%s", cgit_root, cgit_query_repo)) || 
-            cgit_read_config(".git/info/cgit", cgit_repo_config_cb)) {
+            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);
                htmlf(cgit_lib_error, "Unable to scan repository",
                      strerror(errno));
                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);
        if (!cgit_query_page)
                cgit_print_repo_summary();
        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))
+        htmlfd = item->fd;
-                die("Error reading config: %d %s", errno, strerror(errno));
+        item->st.st_mtime = time(NULL);
-        chdir(cgit_root);
-        cgit_parse_query(getenv("QUERY_STRING"), cgit_querystring_cb);
        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;
 }
author	Lars Hjemli <hjemli@gmail.com>	2006-12-10 21:31:36 (UTC)
committer	Lars Hjemli <hjemli@gmail.com>	2006-12-10 21:31:36 (UTC)
commit	25105d7ecaba474d4b7c364ebb586aac3dfc5abb (patch) (unidiff)
tree	8beb08db1399b8efb8c7fbcd936044ae7fc232e6 /cgit.c
parent	856c026e221d8ed82c5b75bc8da4bd65e89ea953 (diff)
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