hook: include hooks from the config

Teach the hook.[hc] library to parse configs to populate the list of
hooks to run for a given event.

Multiple commands can be specified for a given hook by providing
"hook.<friendly-name>.command = <path-to-hook>" and
"hook.<friendly-name>.event = <hook-event>" lines.

Hooks will be started in config order of the "hook.<name>.event"
lines and will be run sequentially (.jobs == 1) like before.
Running the hooks in parallel will be enabled in a future patch.

The "traditional" hook from the hookdir is run last, if present.

A strmap cache is added to struct repository to avoid re-reading
the configs on each rook run. This is useful for hooks like the
ref-transaction which gets executed multiple times per process.

Examples:

  $ git config --get-regexp "^hook\."
  hook.bar.command=~/bar.sh
  hook.bar.event=pre-commit

  # Will run ~/bar.sh, then .git/hooks/pre-commit
  $ git hook run pre-commit

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/hook.h b/hook.h
index fea221f87d..e949f5d488 100644
--- a/hook.h
+++ b/hook.h
@@ -3,6 +3,7 @@
 #include "strvec.h"
 #include "run-command.h"
 #include "string-list.h"
+#include "strmap.h"
 
 struct repository;
 
@@ -10,17 +11,22 @@ struct repository;
  * Represents a hook command to be run.
  * Hooks can be:
  * 1. "traditional" (found in the hooks directory)
- * 2. "configured" (defined in Git's configuration, not yet implemented).
+ * 2. "configured" (defined in Git's configuration via hook.<name>.event).
  * The 'kind' field determines which part of the union 'u' is valid.
  */
 struct hook {
 	enum {
 		HOOK_TRADITIONAL,
+		HOOK_CONFIGURED,
 	} kind;
 	union {
 		struct {
 			const char *path;
 		} traditional;
+		struct {
+			const char *friendly_name;
+			const char *command;
+		} configured;
 	} u;
 
 	/**
@@ -186,6 +192,12 @@ struct string_list *list_hooks(struct repository *r, const char *hookname,
 void hook_list_clear(struct string_list *hooks, cb_data_free_fn cb_data_free);
 
 /**
+ * Frees the hook configuration cache stored in `struct repository`.
+ * Called by repo_clear().
+ */
+void hook_cache_clear(struct strmap *cache);
+
+/**
  * Returns the path to the hook file, or NULL if the hook is missing
  * or disabled. Note that this points to static storage that will be
  * overwritten by further calls to find_hook and run_hook_*.