From a12f07792f8fc0a96710e22f18752f7bb8f212b9 Mon Sep 17 00:00:00 2001
From: Oran Agra <oran@redislabs.com>
Date: Wed, 23 Oct 2019 12:08:47 +0300
Subject: [PATCH] Module API for explicit SignalModifiedKey instead of implicit
one.
This commit also fixes an uninitialized module struct member (that luckily never got released)
---
src/module.c | 19 ++++++++++++++++++-
src/redismodule.h | 6 ++++++
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/src/module.c b/src/module.c
index 971bf5c08..21bab5cdf 100644
--- a/src/module.c
+++ b/src/module.c
@@ -322,6 +322,13 @@ static struct RedisModuleForkInfo {
#define REDISMODULE_ARGV_NO_AOF (1<<1)
#define REDISMODULE_ARGV_NO_REPLICAS (1<<2)
+/* Determine whether Redis should signalModifiedKey implicitly.
+ * In case 'ctx' has no 'module' member (and therefore no module->options),
+ * we assume default behavior, that is, Redis signals.
+ * (see RM_GetThreadSafeContext) */
+#define SHOULD_SIGNAL_MODIFIED_KEYS(ctx) \
+ ctx->module? !(ctx->module->options & REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED) : 1
+
/* Server events hooks data structures and defines: this modules API
* allow modules to subscribe to certain events in Redis, such as
* the start and end of an RDB or AOF save, the change of role in replication,
@@ -822,6 +829,7 @@ void RM_SetModuleAttribs(RedisModuleCtx *ctx, const char *name, int ver, int api
module->filters = listCreate();
module->in_call = 0;
module->in_hook = 0;
+ module->options = 0;
ctx->module = module;
}
@@ -852,6 +860,12 @@ void RM_SetModuleOptions(RedisModuleCtx *ctx, int options) {
ctx->module->options = options;
}
+/* Signals that the key is modified from user's perspective (i.e. invalidate WATCH). */
+int RM_SignalModifiedKey(RedisModuleCtx *ctx, RedisModuleString *keyname) {
+ signalModifiedKey(ctx->client->db,keyname);
+ return REDISMODULE_OK;
+}
+
/* --------------------------------------------------------------------------
* Automatic memory management for modules
* -------------------------------------------------------------------------- */
@@ -1843,7 +1857,9 @@ void *RM_OpenKey(RedisModuleCtx *ctx, robj *keyname, int mode) {
/* Close a key handle. */
void RM_CloseKey(RedisModuleKey *key) {
if (key == NULL) return;
- if (key->mode & REDISMODULE_WRITE) signalModifiedKey(key->db,key->key);
+ int signal = SHOULD_SIGNAL_MODIFIED_KEYS(key->ctx);
+ if ((key->mode & REDISMODULE_WRITE) && signal)
+ signalModifiedKey(key->db,key->key);
/* TODO: if (key->iter) RM_KeyIteratorStop(kp); */
RM_ZsetRangeStop(key);
decrRefCount(key->key);
@@ -6449,6 +6465,7 @@ void moduleRegisterCoreAPI(void) {
REGISTER_API(ModuleTypeGetValue);
REGISTER_API(IsIOError);
REGISTER_API(SetModuleOptions);
+ REGISTER_API(SignalModifiedKey);
REGISTER_API(SaveUnsigned);
REGISTER_API(LoadUnsigned);
REGISTER_API(SaveSigned);
diff --git a/src/redismodule.h b/src/redismodule.h
index 4b63a227c..9fe0f5eba 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -161,6 +161,10 @@ typedef uint64_t RedisModuleTimerID;
/* Declare that the module can handle errors with RedisModule_SetModuleOptions. */
#define REDISMODULE_OPTIONS_HANDLE_IO_ERRORS (1<<0)
+/* When set, Redis will not call RedisModule_SignalModifiedKey(), implicitly in
+ * RedisModule_CloseKey, and the module needs to do that when manually when keys
+ * are modified from the user's sperspective, to invalidate WATCH. */
+#define REDISMODULE_OPTION_NO_IMPLICIT_SIGNAL_MODIFIED (1<<1)
/* Server events definitions. */
#define REDISMODULE_EVENT_REPLICATION_ROLE_CHANGED 0
@@ -434,6 +438,7 @@ RedisModuleType *REDISMODULE_API_FUNC(RedisModule_ModuleTypeGetType)(RedisModule
void *REDISMODULE_API_FUNC(RedisModule_ModuleTypeGetValue)(RedisModuleKey *key);
int REDISMODULE_API_FUNC(RedisModule_IsIOError)(RedisModuleIO *io);
void REDISMODULE_API_FUNC(RedisModule_SetModuleOptions)(RedisModuleCtx *ctx, int options);
+int REDISMODULE_API_FUNC(RedisModule_SignalModifiedKey)(RedisModuleCtx *ctx, RedisModuleString *keyname);
void REDISMODULE_API_FUNC(RedisModule_SaveUnsigned)(RedisModuleIO *io, uint64_t value);
uint64_t REDISMODULE_API_FUNC(RedisModule_LoadUnsigned)(RedisModuleIO *io);
void REDISMODULE_API_FUNC(RedisModule_SaveSigned)(RedisModuleIO *io, int64_t value);
@@ -629,6 +634,7 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
REDISMODULE_GET_API(ModuleTypeGetValue);
REDISMODULE_GET_API(IsIOError);
REDISMODULE_GET_API(SetModuleOptions);
+ REDISMODULE_GET_API(SignalModifiedKey);
REDISMODULE_GET_API(SaveUnsigned);
REDISMODULE_GET_API(LoadUnsigned);
REDISMODULE_GET_API(SaveSigned);