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>

7 files changed, 169 insertions, 110 deletions

diff --git a/Makefile b/Makefile
index 7102908..d9ff7d8 100644
--- a/Makefile
+++ b/Makefile
@@ -13,13 +13,13 @@ GIT_URL = http://www.kernel.org/pub/software/scm/git/git-$(GIT_VER).tar.bz2
 -include cgit.conf
 
 
 EXTLIBS = git/libgit.a git/xdiff/lib.a -lz -lcrypto
 OBJECTS = shared.o cache.o parsing.o html.o ui-shared.o ui-repolist.o \
         ui-summary.o ui-log.o ui-tree.o ui-commit.o ui-diff.o \
-        ui-snapshot.o ui-blob.o ui-tag.o ui-refs.o ui-patch.o
+        ui-snapshot.o ui-blob.o ui-tag.o ui-refs.o ui-patch.o cmd.o
 
 
 ifdef NEEDS_LIBICONV
         EXTLIBS += -liconv
 endif
 
diff --git a/cgit.c b/cgit.c
index a83f0be..79e0e43 100644
--- a/cgit.c
+++ b/cgit.c
@@ -78,117 +78,90 @@ char *find_default_branch(struct cgit_repo *repo)
         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;
@@ -206,16 +179,13 @@ static void cgit_fill_cache(struct cacheitem *item, int use_cache)
                 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");
diff --git a/cgit.h b/cgit.h
index 40e2d40..295441b 100644
--- a/cgit.h
+++ b/cgit.h
@@ -17,25 +17,12 @@
 #include <archive.h>
 #include <xdiff/xdiff.h>
 #include <utf8.h>
 
 
 /*
- * The valid cgit repo-commands
- */
-#define CMD_LOG      1
-#define CMD_COMMIT   2
-#define CMD_DIFF     3
-#define CMD_TREE     4
-#define CMD_BLOB     5
-#define CMD_SNAPSHOT 6
-#define CMD_TAG      7
-#define CMD_REFS     8
-#define CMD_PATCH    9
-
-/*
  * Dateformats used on misc. pages
  */
 #define FMT_LONGDATE "%Y-%m-%d %H:%M:%S"
 #define FMT_SHORTDATE "%Y-%m-%d"
 
 
@@ -194,13 +181,12 @@ extern const char *cgit_version;
 
 extern struct cgit_repolist cgit_repolist;
 extern struct cgit_context ctx;
 extern int cgit_cmd;
 
 extern void cgit_prepare_context(struct cgit_context *ctx);
-extern int cgit_get_cmd_index(const char *cmd);
 extern struct cgit_repo *cgit_get_repoinfo(const char *url);
 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);
diff --git a/cmd.c b/cmd.c
new file mode 100644
index 0000000..489a11c
--- a/dev/null
+++ b/cmd.c
@@ -0,0 +1,101 @@
+/* cmd.c: the cgit command dispatcher
+ *
+ * Copyright (C) 2008 Lars Hjemli
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include "cmd.h"
+
+static void blob_fn(struct cgit_context *ctx)
+{
+        cgit_print_blob(ctx->qry.sha1, ctx->qry.path);
+}
+
+static void commit_fn(struct cgit_context *ctx)
+{
+        cgit_print_commit(ctx->qry.sha1);
+}
+
+static void diff_fn(struct cgit_context *ctx)
+{
+        cgit_print_diff(ctx->qry.sha1, ctx->qry.sha2, ctx->qry.path);
+}
+
+static void repolist_fn(struct cgit_context *ctx)
+{
+        cgit_print_repolist();
+}
+
+static void log_fn(struct cgit_context *ctx)
+{
+        cgit_print_log(ctx->qry.sha1, ctx->qry.ofs, ctx->cfg.max_commit_count,
+                       ctx->qry.grep, ctx->qry.search, ctx->qry.path, 1);
+}
+
+static void patch_fn(struct cgit_context *ctx)
+{
+        cgit_print_patch(ctx->qry.sha1);
+}
+
+static void refs_fn(struct cgit_context *ctx)
+{
+        cgit_print_refs();
+}
+
+static void snapshot_fn(struct cgit_context *ctx)
+{
+        cgit_print_snapshot(ctx->qry.head, ctx->qry.sha1,
+                            cgit_repobasename(ctx->repo->url), ctx->qry.path,
+                            ctx->repo->snapshots);
+}
+
+static void summary_fn(struct cgit_context *ctx)
+{
+        cgit_print_summary();
+}
+
+static void tag_fn(struct cgit_context *ctx)
+{
+        cgit_print_tag(ctx->qry.sha1);
+}
+
+static void tree_fn(struct cgit_context *ctx)
+{
+        cgit_print_tree(ctx->qry.sha1, ctx->qry.path);
+}
+
+#define def_cmd(name, want_repo, want_layout) \
+        {#name, name##_fn, want_repo, want_layout}
+
+struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx)
+{
+        static struct cgit_cmd cmds[] = {
+                def_cmd(blob, 1, 0),
+                def_cmd(commit, 1, 1),
+                def_cmd(diff, 1, 1),
+                def_cmd(log, 1, 1),
+                def_cmd(patch, 1, 0),
+                def_cmd(refs, 1, 1),
+                def_cmd(repolist, 0, 0),
+                def_cmd(snapshot, 1, 0),
+                def_cmd(summary, 1, 1),
+                def_cmd(tag, 1, 1),
+                def_cmd(tree, 1, 1),
+        };
+        int i;
+
+        if (ctx->qry.page == NULL) {
+                if (ctx->repo)
+                        ctx->qry.page = "summary";
+                else
+                        ctx->qry.page = "repolist";
+        }
+
+        for(i = 0; i < sizeof(cmds)/sizeof(*cmds); i++)
+                if (!strcmp(ctx->qry.page, cmds[i].name))
+                        return &cmds[i];
+        return NULL;
+}
diff --git a/cmd.h b/cmd.h
new file mode 100644
index 0000000..ec9e691
--- a/dev/null
+++ b/cmd.h
@@ -0,0 +1,15 @@
+#ifndef CMD_H
+#define CMD_H
+
+typedef void (*cgit_cmd_fn)(struct cgit_context *ctx);
+
+struct cgit_cmd {
+        const char *name;
+        cgit_cmd_fn fn;
+        unsigned int want_repo:1,
+                want_layout:1;
+};
+
+extern struct cgit_cmd *cgit_get_cmd(struct cgit_context *ctx);
+
+#endif /* CMD_H */
diff --git a/parsing.c b/parsing.c
index 027f06b..8dce488 100644
--- a/parsing.c
+++ b/parsing.c
@@ -167,14 +167,14 @@ void cgit_parse_url(const char *url)
                 p = strchr(cmd + 1, '/');
                 if (p) {
                         p[0] = '\0';
                         if (p[1])
                                 ctx.qry.path = trim_end(p + 1, '/');
                 }
-                cgit_cmd = cgit_get_cmd_index(cmd + 1);
-                ctx.qry.page = xstrdup(cmd + 1);
+                if (cmd[1])
+                        ctx.qry.page = xstrdup(cmd + 1);
                 return;
         }
 }
 
 char *substr(const char *head, const char *tail)
 {
diff --git a/shared.c b/shared.c
index 539d533..67eb67b 100644
--- a/shared.c
+++ b/shared.c
@@ -37,24 +37,12 @@ void cgit_prepare_context(struct cgit_context *ctx)
         ctx->cfg.script_name = CGIT_SCRIPT_NAME;
         ctx->page.mimetype = "text/html";
         ctx->page.charset = PAGE_ENCODING;
         ctx->page.filename = NULL;
 }
 
-int cgit_get_cmd_index(const char *cmd)
-{
-        static char *cmds[] = {"log", "commit", "diff", "tree", "blob",
-                               "snapshot", "tag", "refs", "patch", NULL};
-        int i;
-
-        for(i = 0; cmds[i]; i++)
-                if (!strcmp(cmd, cmds[i]))
-                        return i + 1;
-        return 0;
-}
-
 int chk_zero(int result, char *msg)
 {
         if (result != 0)
                 die("%s: %s", msg, strerror(errno));
         return result;
 }
@@ -213,13 +201,12 @@ void cgit_querystring_cb(const char *name, const char *value)
 {
         if (!strcmp(name,"r")) {
                 ctx.qry.repo = xstrdup(value);
                 ctx.repo = cgit_get_repoinfo(value);
         } else if (!strcmp(name, "p")) {
                 ctx.qry.page = xstrdup(value);
-                cgit_cmd = cgit_get_cmd_index(value);
         } else if (!strcmp(name, "url")) {
                 cgit_parse_url(value);
         } else if (!strcmp(name, "qt")) {
                 ctx.qry.grep = xstrdup(value);
         } else if (!strcmp(name, "q")) {
                 ctx.qry.search = xstrdup(value);