miva-redis

Redis client for Miva. This only supports running on Linux.

Development

Simply run "docker-compose up" in this directory to spool up a dev environment for working on this module. Access the wwwroot folder by going to http://localhost:8080. All .mv files in the wwwroot directory will be compiled by the mivascript compiler whenever a change is detected. All .mv files have access to the miva-redis module.

Containers

• cpp-compiler
  • Watches for changes to the src/**/*.cpp files, and runs "make" when changes are directed. Output is set to ./src/bin, and also copied to the /data/builtins directory
• miva-compiler
  • Watches for changes to the wwwroot/**/*.mv files, and compiles them into .mvc files on change. References the /data/builtins directory so that it can see the compiled miva-redis binary.
• miva-empresa
  • An apache server configured with the empresa engine in CGI mode, seving out the ./wwwroot directory. References the /data/builtins directory so that it can execute the miva-redis binary.
• redis
  • An instance of a redis server available in the miva-empresa container using the hostname "redis".

Usage

1. Compile for your target architecture/linux kernel/distro
2. Either:
   • Copy miva-redis.so into your builtins directory for your mivavm OR
   • Add <BUILTIN-LIB LIBRARY = "/path/to/miva-redis.so"> to your mivavm.conf file
3. Add a redis.dat file to your mivadata directory with either of the formats:
   • host:port OR
   • host:port:db where db is the database index to connect to
4. Congrats! You can now use the redis_* commands! miva-redis will use the redis.dat file to automatically connect to the server the first time you try to use a redis_* command. If redis.dat doesn't exist, or there is an error, all redis_* commands will fail silently.

Functions

Low Level

redis_reply redis_command(string command, string args)

command: the command format to send to redis. You can use ? as substitions.

args: a comma seperated list of variable names, all starting with either l. or g., that will be substituted into ? placeholders for the command.

Returns 0 on error, otherwise returns a redis_reply. See formatRedisReply and https://github.com/redis/hiredis#using-replies for more information.

Examples

<MvAssign name="l.data" value="HEY THERE!" />
<MvAssign name="l._" value="{redis_command('SET key ?', 'l.data')}" />

<MvAssign name="l.data" value="{redis_command('GET key', '')}" />
<MvEval expr="{l.data:string}" />

void redis_command_append(string command, string args)

See redis_command and https://github.com/redis/hiredis#pipelining

int redis_error(string* message)

message: if there is an error, this variable is filled with the error message.

If there is an error, returns a non-zero error code. Otherwise, returns 0.

void redis_error_clear()

Clears the last redis error.

int redis_free()

Disconnects from redis. Returns 1 on success, 0 on failure. Note that you shouldn't have to call this function. I don't know why I made it.

int redis_get_reply(redis_reply* reply)

See https://github.com/redis/hiredis#pipelining

int redis_is_enabled()

If a redis conneciton has not yet been attempted, attempts to connect using the information provided in mivadata/redis.dat. If no mivadata/redis.dat file is present, or the connection fails, returns 0.

If a redis connection has been attempted, returns 1 or 0 depending on if the connection was successful.

High Level

int redis_append(string key, string* value)

Wrapper around APPEND.

key: the key to append to.

value: a reference to the string to append.

Returns 0 on error, 1 on success.

int redis_del(string key)

Wrapper around DEL.

key: the key to delete (todo: accept arrays too).

Returns 0 on error, 1 on success.

int redis_get(string key, string* ret)

Wrapper around GET.

key: the key to get.

ret: the value of the key will be placed in this variable.

Returns 0 on error, -1 if the key was not found, and 1 if the key was found.

int redis_set(string key, string* value)

Wrapper around SET.

key: the key to set.

value: a reference to the string to set the key to.

Returns 0 on error, 1 on success.

int redis_setex(string key, string value var, int expires)

Wrapper around SETEX.

key: the key to set.

value: a reference to the string to set the key to.

expires: the expiration of the key in seconds.