Add command dispatcher

This simplifies the code in cgit.c and makes it easier to extend cgit with
new pages/commands.

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

1 files changed, 50 insertions, 80 deletions

diff --git a/cgit.c b/cgit.c
index a83f0be..79e0e43 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1,332 +1,302 @@
 /* cgit.c: cgi for the git scm
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "cmd.h"
 
 static int cgit_prepare_cache(struct cacheitem *item)
 {
         if (!ctx.repo && ctx.qry.repo) {
                 ctx.page.title = fmt("%s - %s", ctx.cfg.root_title,
                                       "Bad request");
                 cgit_print_http_headers(&ctx);
                 cgit_print_docstart(&ctx);
                 cgit_print_pageheader(&ctx);
                 cgit_print_error(fmt("Unknown repo: %s", ctx.qry.repo));
                 cgit_print_docend();
                 return 0;
         }
 
         if (!ctx.repo) {
                 item->name = xstrdup(fmt("%s/index.html", ctx.cfg.cache_root));
                 item->ttl = ctx.cfg.cache_root_ttl;
                 return 1;
         }
 
         if (!cgit_cmd) {
                 item->name = xstrdup(fmt("%s/%s/index.%s.html", ctx.cfg.cache_root,
                                          cache_safe_filename(ctx.repo->url),
                                          cache_safe_filename(ctx.qry.raw)));
                 item->ttl = ctx.cfg.cache_repo_ttl;
         } else {
                 item->name = xstrdup(fmt("%s/%s/%s/%s.html", ctx.cfg.cache_root,
                                          cache_safe_filename(ctx.repo->url),
                                          ctx.qry.page,
                                          cache_safe_filename(ctx.qry.raw)));
                 if (ctx.qry.has_symref)
                         item->ttl = ctx.cfg.cache_dynamic_ttl;
                 else if (ctx.qry.has_sha1)
                         item->ttl = ctx.cfg.cache_static_ttl;
                 else
                         item->ttl = ctx.cfg.cache_repo_ttl;
         }
         return 1;
 }
 
 struct refmatch {
         char *req_ref;
         char *first_ref;
         int match;
 };
 
 int find_current_ref(const char *refname, const unsigned char *sha1,
                      int flags, void *cb_data)
 {
         struct refmatch *info;
 
         info = (struct refmatch *)cb_data;
         if (!strcmp(refname, info->req_ref))
                 info->match = 1;
         if (!info->first_ref)
                 info->first_ref = xstrdup(refname);
         return info->match;
 }
 
 char *find_default_branch(struct cgit_repo *repo)
 {
         struct refmatch info;
 
         info.req_ref = repo->defbranch;
         info.first_ref = NULL;
         info.match = 0;
         for_each_branch_ref(find_current_ref, &info);
         if (info.match)
                 return info.req_ref;
         else
                 return info.first_ref;
 }
 
-static void cgit_print_repo_page()
+static int prepare_repo_cmd(struct cgit_context *ctx)
 {
         char *tmp;
-        int show_search;
         unsigned char sha1[20];
         int nongit = 0;
 
-        setenv("GIT_DIR", ctx.repo->path, 1);
+        setenv("GIT_DIR", ctx->repo->path, 1);
         setup_git_directory_gently(&nongit);
         if (nongit) {
-                ctx.page.title = fmt("%s - %s", ctx.cfg.root_title,
-                                     "config error");
-                tmp = fmt("Not a git repository: '%s'", ctx.repo->path);
-                ctx.repo = NULL;
-                cgit_print_http_headers(&ctx);
-                cgit_print_docstart(&ctx);
-                cgit_print_pageheader(&ctx);
+                ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
+                                      "config error");
+                tmp = fmt("Not a git repository: '%s'", ctx->repo->path);
+                ctx->repo = NULL;
+                cgit_print_http_headers(ctx);
+                cgit_print_docstart(ctx);
+                cgit_print_pageheader(ctx);
                 cgit_print_error(tmp);
                 cgit_print_docend();
-                return;
+                return 1;
         }
+        ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
 
-        ctx.page.title = fmt("%s - %s", ctx.repo->name, ctx.repo->desc);
-        show_search = 0;
-
-        if (!ctx.qry.head) {
-                ctx.qry.head = xstrdup(find_default_branch(ctx.repo));
-                ctx.repo->defbranch = ctx.qry.head;
+        if (!ctx->qry.head) {
+                ctx->qry.head = xstrdup(find_default_branch(ctx->repo));
+                ctx->repo->defbranch = ctx->qry.head;
         }
 
-        if (!ctx.qry.head) {
-                cgit_print_http_headers(&ctx);
-                cgit_print_docstart(&ctx);
-                cgit_print_pageheader(&ctx);
+        if (!ctx->qry.head) {
+                cgit_print_http_headers(ctx);
+                cgit_print_docstart(ctx);
+                cgit_print_pageheader(ctx);
                 cgit_print_error("Repository seems to be empty");
                 cgit_print_docend();
-                return;
+                return 1;
         }
 
-        if (get_sha1(ctx.qry.head, sha1)) {
-                tmp = xstrdup(ctx.qry.head);
-                ctx.qry.head = ctx.repo->defbranch;
-                cgit_print_http_headers(&ctx);
-                cgit_print_docstart(&ctx);
-                cgit_print_pageheader(&ctx);
+        if (get_sha1(ctx->qry.head, sha1)) {
+                tmp = xstrdup(ctx->qry.head);
+                ctx->qry.head = ctx->repo->defbranch;
+                cgit_print_http_headers(ctx);
+                cgit_print_docstart(ctx);
+                cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("Invalid branch: %s", tmp));
                 cgit_print_docend();
-                return;
+                return 1;
         }
+        return 0;
+}
 
-        if ((cgit_cmd == CMD_SNAPSHOT) && ctx.repo->snapshots) {
-                cgit_print_snapshot(ctx.qry.head, ctx.qry.sha1,
-                                    cgit_repobasename(ctx.repo->url),
-                                    ctx.qry.path,
-                                    ctx.repo->snapshots );
+static void process_request(struct cgit_context *ctx)
+{
+        struct cgit_cmd *cmd;
+
+        cmd = cgit_get_cmd(ctx);
+        if (!cmd) {
+                ctx->page.title = "cgit error";
+                ctx->repo = NULL;
+                cgit_print_http_headers(ctx);
+                cgit_print_docstart(ctx);
+                cgit_print_pageheader(ctx);
+                cgit_print_error("Invalid request");
+                cgit_print_docend();
                 return;
         }
 
-        if (cgit_cmd == CMD_PATCH) {
-                cgit_print_patch(ctx.qry.sha1);
+        if (cmd->want_repo && prepare_repo_cmd(ctx))
                 return;
-        }
 
-        if (cgit_cmd == CMD_BLOB) {
-                cgit_print_blob(ctx.qry.sha1, ctx.qry.path);
-                return;
+        if (cmd->want_layout) {
+                cgit_print_http_headers(ctx);
+                cgit_print_docstart(ctx);
+                cgit_print_pageheader(ctx);
         }
 
-        show_search = (cgit_cmd == CMD_LOG);
-        cgit_print_http_headers(&ctx);
-        cgit_print_docstart(&ctx);
-        if (!cgit_cmd) {
-                cgit_print_pageheader(&ctx);
-                cgit_print_summary();
-                cgit_print_docend();
-                return;
-        }
+        cmd->fn(ctx);
 
-        cgit_print_pageheader(&ctx);
-
-        switch(cgit_cmd) {
-        case CMD_LOG:
-                cgit_print_log(ctx.qry.sha1, ctx.qry.ofs,
-                               ctx.cfg.max_commit_count, ctx.qry.grep, ctx.qry.search,
-                               ctx.qry.path, 1);
-                break;
-        case CMD_TREE:
-                cgit_print_tree(ctx.qry.sha1, ctx.qry.path);
-                break;
-        case CMD_COMMIT:
-                cgit_print_commit(ctx.qry.sha1);
-                break;
-        case CMD_REFS:
-                cgit_print_refs();
-                break;
-        case CMD_TAG:
-                cgit_print_tag(ctx.qry.sha1);
-                break;
-        case CMD_DIFF:
-                cgit_print_diff(ctx.qry.sha1, ctx.qry.sha2, ctx.qry.path);
-                break;
-        default:
-                cgit_print_error("Invalid request");
-        }
-        cgit_print_docend();
+        if (cmd->want_layout)
+                cgit_print_docend();
 }
 
 static long ttl_seconds(long ttl)
 {
         if (ttl<0)
                 return 60 * 60 * 24 * 365;
         else
                 return ttl * 60;
 }
 
 static void cgit_fill_cache(struct cacheitem *item, int use_cache)
 {
         int stdout2;
 
         if (use_cache) {
                 stdout2 = chk_positive(dup(STDOUT_FILENO),
                                        "Preserving STDOUT");
                 chk_zero(close(STDOUT_FILENO), "Closing STDOUT");
                 chk_positive(dup2(item->fd, STDOUT_FILENO), "Dup2(cachefile)");
         }
 
         ctx.page.modified = time(NULL);
         ctx.page.expires = ctx.page.modified + ttl_seconds(item->ttl);
-        if (ctx.repo)
-                cgit_print_repo_page();
-        else
-                cgit_print_repolist();
+        process_request(&ctx);
 
         if (use_cache) {
                 chk_zero(close(STDOUT_FILENO), "Close redirected STDOUT");
                 chk_positive(dup2(stdout2, STDOUT_FILENO),
                              "Restoring original STDOUT");
                 chk_zero(close(stdout2), "Closing temporary STDOUT");
         }
 }
 
 static void cgit_check_cache(struct cacheitem *item)
 {
         int i = 0;
 
  top:
         if (++i > ctx.cfg.max_lock_attempts) {
                 die("cgit_refresh_cache: unable to lock %s: %s",
                     item->name, strerror(errno));
         }
         if (!cache_exist(item)) {
                 if (!cache_lock(item)) {
                         sleep(1);
                         goto top;
                 }
                 if (!cache_exist(item)) {
                         cgit_fill_cache(item, 1);
                         cache_unlock(item);
                 } else {
                         cache_cancel_lock(item);
                 }
         } else if (cache_expired(item) && cache_lock(item)) {
                 if (cache_expired(item)) {
                         cgit_fill_cache(item, 1);
                         cache_unlock(item);
                 } else {
                         cache_cancel_lock(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);
 }
 
 static void cgit_parse_args(int argc, const char **argv)
 {
         int i;
 
         for (i = 1; i < argc; i++) {
                 if (!strncmp(argv[i], "--cache=", 8)) {
                         ctx.cfg.cache_root = xstrdup(argv[i]+8);
                 }
                 if (!strcmp(argv[i], "--nocache")) {
                         ctx.cfg.nocache = 1;
                 }
                 if (!strncmp(argv[i], "--query=", 8)) {
                         ctx.qry.raw = xstrdup(argv[i]+8);
                 }
                 if (!strncmp(argv[i], "--repo=", 7)) {
                         ctx.qry.repo = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--page=", 7)) {
                         ctx.qry.page = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--head=", 7)) {
                         ctx.qry.head = xstrdup(argv[i]+7);
                         ctx.qry.has_symref = 1;
                 }
                 if (!strncmp(argv[i], "--sha1=", 7)) {
                         ctx.qry.sha1 = xstrdup(argv[i]+7);
                         ctx.qry.has_sha1 = 1;
                 }
                 if (!strncmp(argv[i], "--ofs=", 6)) {
                         ctx.qry.ofs = atoi(argv[i]+6);
                 }
         }
 }
 
 int main(int argc, const char **argv)
 {
         struct cacheitem item;
         const char *cgit_config_env = getenv("CGIT_CONFIG");
 
         cgit_prepare_context(&ctx);
         item.st.st_mtime = time(NULL);
         cgit_repolist.length = 0;
         cgit_repolist.count = 0;
         cgit_repolist.repos = NULL;
 
         cgit_read_config(cgit_config_env ? cgit_config_env : CGIT_CONFIG,
                          cgit_global_config_cb);
         if (getenv("SCRIPT_NAME"))
                 ctx.cfg.script_name = xstrdup(getenv("SCRIPT_NAME"));
         if (getenv("QUERY_STRING"))
                 ctx.qry.raw = xstrdup(getenv("QUERY_STRING"));
         cgit_parse_args(argc, argv);
         cgit_parse_query(ctx.qry.raw, cgit_querystring_cb);
         if (!cgit_prepare_cache(&item))
                 return 0;
         if (ctx.cfg.nocache) {
                 cgit_fill_cache(&item, 0);
         } else {
                 cgit_check_cache(&item);
                 cgit_print_cache(&item);
         }
         return 0;
 }