valkey/tests/modules/rdbloadsave.c
Ozan Tezcan e55568edb5
Add RM_RdbLoad and RM_RdbSave module API functions (#11852)
Add `RM_RdbLoad()` and `RM_RdbSave()` to load/save RDB files from the module API. 

In our use case, we have our clustering implementation as a module. As part of this
implementation, the module needs to trigger RDB save operation at specific points.
Also, this module delivers RDB files to other nodes (not using Redis' replication).
When a node receives an RDB file, it should be able to load the RDB. Currently,
there is no module API to save/load RDB files. 


This PR adds four new APIs:
```c
RedisModuleRdbStream *RM_RdbStreamCreateFromFile(const char *filename);
void RM_RdbStreamFree(RedisModuleRdbStream *stream);

int RM_RdbLoad(RedisModuleCtx *ctx, RedisModuleRdbStream *stream, int flags);
int RM_RdbSave(RedisModuleCtx *ctx, RedisModuleRdbStream *stream, int flags);
```

The first step is to create a `RedisModuleRdbStream` object. This PR provides a function to
create RedisModuleRdbStream from the filename. (You can load/save RDB with the filename).
In the future, this API can be extended if needed: 
e.g., `RM_RdbStreamCreateFromFd()`, `RM_RdbStreamCreateFromSocket()` to save/load
RDB from an `fd` or a `socket`. 


Usage:
```c
/* Save RDB */
RedisModuleRdbStream *stream = RedisModule_RdbStreamCreateFromFile("example.rdb");
RedisModule_RdbSave(ctx, stream, 0);
RedisModule_RdbStreamFree(stream);

/* Load RDB */
RedisModuleRdbStream *stream = RedisModule_RdbStreamCreateFromFile("example.rdb");
RedisModule_RdbLoad(ctx, stream, 0);
RedisModule_RdbStreamFree(stream);
```
2023-04-09 12:07:32 +03:00

163 lines
4.7 KiB
C

#include "redismodule.h"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <memory.h>
#include <errno.h>
/* Sanity tests to verify inputs and return values. */
int sanity(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
REDISMODULE_NOT_USED(argv);
REDISMODULE_NOT_USED(argc);
RedisModuleRdbStream *s = RedisModule_RdbStreamCreateFromFile("dbnew.rdb");
/* NULL stream should fail. */
if (RedisModule_RdbLoad(ctx, NULL, 0) == REDISMODULE_OK || errno != EINVAL) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
/* Invalid flags should fail. */
if (RedisModule_RdbLoad(ctx, s, 188) == REDISMODULE_OK || errno != EINVAL) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
/* Missing file should fail. */
if (RedisModule_RdbLoad(ctx, s, 0) == REDISMODULE_OK || errno != ENOENT) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
/* Save RDB file. */
if (RedisModule_RdbSave(ctx, s, 0) != REDISMODULE_OK || errno != 0) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
/* Load the saved RDB file. */
if (RedisModule_RdbLoad(ctx, s, 0) != REDISMODULE_OK || errno != 0) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
RedisModule_ReplyWithSimpleString(ctx, "OK");
out:
RedisModule_RdbStreamFree(s);
return REDISMODULE_OK;
}
int cmd_rdbsave(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
if (argc != 2) {
RedisModule_WrongArity(ctx);
return REDISMODULE_OK;
}
size_t len;
const char *filename = RedisModule_StringPtrLen(argv[1], &len);
char tmp[len + 1];
memcpy(tmp, filename, len);
tmp[len] = '\0';
RedisModuleRdbStream *stream = RedisModule_RdbStreamCreateFromFile(tmp);
if (RedisModule_RdbSave(ctx, stream, 0) != REDISMODULE_OK || errno != 0) {
RedisModule_ReplyWithError(ctx, strerror(errno));
goto out;
}
RedisModule_ReplyWithSimpleString(ctx, "OK");
out:
RedisModule_RdbStreamFree(stream);
return REDISMODULE_OK;
}
/* Fork before calling RM_RdbSave(). */
int cmd_rdbsave_fork(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
if (argc != 2) {
RedisModule_WrongArity(ctx);
return REDISMODULE_OK;
}
size_t len;
const char *filename = RedisModule_StringPtrLen(argv[1], &len);
char tmp[len + 1];
memcpy(tmp, filename, len);
tmp[len] = '\0';
int fork_child_pid = RedisModule_Fork(NULL, NULL);
if (fork_child_pid < 0) {
RedisModule_ReplyWithError(ctx, strerror(errno));
return REDISMODULE_OK;
} else if (fork_child_pid > 0) {
/* parent */
RedisModule_ReplyWithSimpleString(ctx, "OK");
return REDISMODULE_OK;
}
RedisModuleRdbStream *stream = RedisModule_RdbStreamCreateFromFile(tmp);
int ret = 0;
if (RedisModule_RdbSave(ctx, stream, 0) != REDISMODULE_OK) {
ret = errno;
}
RedisModule_RdbStreamFree(stream);
RedisModule_ExitFromChild(ret);
return REDISMODULE_OK;
}
int cmd_rdbload(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
if (argc != 2) {
RedisModule_WrongArity(ctx);
return REDISMODULE_OK;
}
size_t len;
const char *filename = RedisModule_StringPtrLen(argv[1], &len);
char tmp[len + 1];
memcpy(tmp, filename, len);
tmp[len] = '\0';
RedisModuleRdbStream *stream = RedisModule_RdbStreamCreateFromFile(tmp);
if (RedisModule_RdbLoad(ctx, stream, 0) != REDISMODULE_OK || errno != 0) {
RedisModule_RdbStreamFree(stream);
RedisModule_ReplyWithError(ctx, strerror(errno));
return REDISMODULE_OK;
}
RedisModule_RdbStreamFree(stream);
RedisModule_ReplyWithSimpleString(ctx, "OK");
return REDISMODULE_OK;
}
int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
REDISMODULE_NOT_USED(argv);
REDISMODULE_NOT_USED(argc);
if (RedisModule_Init(ctx, "rdbloadsave", 1, REDISMODULE_APIVER_1) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx, "test.sanity", sanity, "", 0, 0, 0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx, "test.rdbsave", cmd_rdbsave, "", 0, 0, 0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx, "test.rdbsave_fork", cmd_rdbsave_fork, "", 0, 0, 0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx, "test.rdbload", cmd_rdbload, "", 0, 0, 0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
return REDISMODULE_OK;
}