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169 | use extism_pdk::*;
use serde::{Serialize, Deserialize};
use thiserror::Error;
extern "C" {
fn hostPrintln(ptr: u64) -> u64;
}
pub fn println(text: String) {
let mut memory_text: Memory = extism_pdk::Memory::new(text.len());
memory_text.store(text);
unsafe { hostPrintln(memory_text.offset) };
}
extern "C" {
fn hostGetEnv(ptr: u64) -> u64;
}
pub fn get_env(name: String) -> String {
// copy the name of the environment variable to the shared memory
let mut variable_name: Memory = extism_pdk::Memory::new(name.len());
variable_name.store(name);
// call the host function
let offset: u64 = unsafe { hostGetEnv(variable_name.offset) };
// read the value of the result from the shared memory
let variable_value: Memory = extism_pdk::Memory::find(offset).unwrap();
// return the value
return variable_value.to_string().unwrap()
}
#[derive(Serialize, Deserialize, Debug)]
struct RedisClientArguments {
pub id: String,
pub uri: String,
}
#[derive(Serialize, Deserialize, Debug)]
struct RedisArguments {
pub id: String,
pub key: String,
pub value: String,
}
#[derive(Serialize, Deserialize, Debug)]
struct StringResult {
pub success: String,
pub failure: String,
}
#[derive(Error, Debug)]
pub enum RedisError {
#[error("Redis Client issue")]
ClientFailure,
#[error("Store issue")]
StoreFailure,
#[error("Not found")]
NotFound,
}
extern "C" {
fn hostInitRedisClient(offset: u64) -> u64;
}
pub fn init_redis_client(redis_client_id: String, redis_uri: String) -> Result<String, Error> {
// Prepare the arguments for the host function
// with a JSON string:
// {
// "id": "id of the redis client",
// "uri": "redis uri"
// }
let args = RedisClientArguments {
id: redis_client_id,
uri: redis_uri,
};
let json_str: String = serde_json::to_string(&args).unwrap();
// Copy the string value to the shared memory
let mut memory_json_str: Memory = extism_pdk::Memory::new(json_str.len());
memory_json_str.store(json_str);
// Call host function with the offset of the arguments
let offset: u64 = unsafe { hostInitRedisClient(memory_json_str.offset) };
// Get result from the shared memory
// The host function (hostInitRedisClient) returns a JSON buffer:
// {
// "success": "the value associated to the key",
// "failure": "error message if error, else empty"
// }
let memory_result: Memory = extism_pdk::Memory::find(offset).unwrap();
let json_string:String = memory_result.to_string().unwrap();
let result: StringResult = serde_json::from_str(&json_string).unwrap();
if result.failure.is_empty() {
return Ok(result.success);
} else {
return Err(RedisError::ClientFailure.into());
}
}
extern "C" {
fn hostRedisSet(offset: u64) -> u64;
}
pub fn redis_set(redis_client_id: String, key: String, value: String) -> Result<String, Error> {
// Prepare the arguments for the host function
// with a JSON string:
// {
// "id": "id of the redis client",
// "key": "name",
// "value": "Bob Morane"
// }
let args = RedisArguments {
id: redis_client_id,
key: key,
value: value,
};
let json_str: String = serde_json::to_string(&args).unwrap();
// Copy the string value to the shared memory
let mut memory_json_str: Memory = extism_pdk::Memory::new(json_str.len());
memory_json_str.store(json_str);
// Call host function with the offset of the arguments
let offset: u64 = unsafe { hostRedisSet(memory_json_str.offset) };
// Get result from the shared memory
// The host function (hostRedisSet) returns a JSON buffer:
// {
// "success": "the value associated to the key",
// "failure": "error message if error, else empty"
// }
let memory_result: Memory = extism_pdk::Memory::find(offset).unwrap();
let json_string:String = memory_result.to_string().unwrap();
let result: StringResult = serde_json::from_str(&json_string).unwrap();
if result.failure.is_empty() {
return Ok(result.success);
} else {
return Err(RedisError::StoreFailure.into());
}
}
#[plugin_fn]
pub fn hello(_: String) -> FnResult<u64> {
let redis_uri : String = get_env("REDIS_URI".to_string());
let redis_client : Result<String, Error> = init_redis_client("redisDb".to_string(), redis_uri);
match redis_set("redisDb".to_string(), "100".to_string(), "Huey".to_string()) {
Ok(value) => println("🦀 saved value: ".to_string() + &value),
Err(error) => println("😡 error: ".to_string() + &error.to_string()),
}
match redis_set("redisDb".to_string(), "200".to_string(), "Dewey".to_string()) {
Ok(value) => println("🦀 saved value: ".to_string() + &value),
Err(error) => println("😡 error: ".to_string() + &error.to_string()),
}
match redis_set("redisDb".to_string(), "300".to_string(), "Louie".to_string()) {
Ok(value) => println("🦀 saved value: ".to_string() + &value),
Err(error) => println("😡 error: ".to_string() + &error.to_string()),
}
Ok(0)
}
|