feature: support hgetall command

Author: samuelj1519

src/backend/mod.rs

@@ -64,6 +64,10 @@ impl BackendInner {
         let hmap = self.hmap.entry(key).or_default();
         hmap.insert(field, value);
     }
+
+    pub fn hget_all(&self, key: &str) -> Option<DashMap<String, RespFrame>> {
+        self.hmap.get(key).map(|v| v.clone())
+    }
 }
 
 #[cfg(test)]

src/cmd/hgetall.rs

@@ -0,0 +1,121 @@
+use crate::backend::Backend;
+use crate::cmd::{extract_args, validate_command, CommandError, CommandExecutor, RESP_EMPTY};
+use crate::{BulkString, RespArray, RespFrame};
+
+#[derive(Debug)]
+pub struct HGetAll {
+    key: String,
+}
+
+impl CommandExecutor for HGetAll {
+    fn execute(self, backend: &Backend) -> Result<RespFrame, CommandError> {
+        match backend.hget_all(&self.key) {
+            Some(map) => {
+                let mut ret: Vec<RespFrame> = Vec::with_capacity(map.len() * 2);
+                map.iter().all(|item| {
+                    ret.push(BulkString::from(item.key().to_string()).into());
+                    ret.push(item.value().clone());
+                    true
+                });
+                Ok(RespArray::new(ret).into())
+            }
+            None => Ok(RESP_EMPTY.clone()),
+        }
+    }
+}
+
+// hgetall key
+// *2\r\n$7\r\nhgetall\r\n$3\r\nkey\r\n
+impl TryFrom<RespArray> for HGetAll {
+    type Error = CommandError;
+
+    fn try_from(value: RespArray) -> Result<Self, Self::Error> {
+        validate_command(&value, &["hgetall"], 1)?;
+
+        let mut args = extract_args(value, 1)?.into_iter();
+        match args.next() {
+            Some(RespFrame::BulkString(key)) => Ok(HGetAll {
+                key: String::from_utf8(key.to_vec())?,
+            }),
+            _ => Err(CommandError::InvalidArgs("Invalid arguments".to_string())),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::cmd::hset::HSet;
+    use crate::RespDecode;
+    use anyhow::Result;
+    use std::collections::BTreeMap;
+
+    #[test]
+    fn test_hgetall_command() -> Result<()> {
+        let mut cmd = bytes::BytesMut::from(&b"*2\r\n$7\r\nhgetall\r\n$3\r\nkey\r\n"[..]);
+        let cmd = RespArray::decode(&mut cmd)?;
+        let hget_all = HGetAll::try_from(cmd)?;
+        assert_eq!(hget_all.key, "key");
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_hset_and_hgetall_command() -> Result<()> {
+        let backend = Backend::new();
+
+        let mut hset = bytes::BytesMut::from(
+            &b"*4\r\n$4\r\nhset\r\n$3\r\nkey\r\n$5\r\nhello\r\n$5\r\nworld\r\n"[..],
+        );
+        let hset = RespArray::decode(&mut hset)?;
+        let hset = HSet::try_from(hset)?;
+        hset.execute(&backend)?;
+
+        let mut hset = bytes::BytesMut::from(
+            &b"*4\r\n$4\r\nhset\r\n$3\r\nkey\r\n$2\r\nhi\r\n$4\r\nrust\r\n"[..],
+        );
+        let hset = RespArray::decode(&mut hset)?;
+        let hset = HSet::try_from(hset)?;
+        hset.execute(&backend)?;
+
+        let mut hgetall = bytes::BytesMut::from(&b"*2\r\n$7\r\nhgetall\r\n$3\r\nkey\r\n"[..]);
+        let hgetall = RespArray::decode(&mut hgetall)?;
+        let hgetall = HGetAll::try_from(hgetall)?;
+        let resp = hgetall.execute(&backend)?;
+
+        let resp = match resp {
+            RespFrame::Array(array) => array,
+            _ => panic!("Expected Array"),
+        };
+        assert_eq!(resp.len() % 2, 0);
+
+        // 排序
+        let mut sorted_map = BTreeMap::new();
+        resp.iter().enumerate().step_by(2).for_each(|(i, key)| {
+            let key = match key {
+                RespFrame::BulkString(key) => String::from_utf8_lossy(key.as_slice()),
+                _ => panic!("Expected BulkString"),
+            };
+            let value = &resp[i + 1];
+            sorted_map.insert(key.to_string(), value.clone());
+        });
+
+        let mut sorted_resp = Vec::with_capacity(resp.len());
+        sorted_map.iter().for_each(|(key, value)| {
+            sorted_resp.push(BulkString::from(key.to_string()).into());
+            sorted_resp.push(value.clone());
+        });
+
+        assert_eq!(
+            sorted_resp,
+            vec![
+                BulkString::from("hello").into(),
+                BulkString::from("world").into(),
+                BulkString::from("hi").into(),
+                BulkString::from("rust").into()
+            ]
+        );
+
+        Ok(())
+    }
+}

src/cmd/mod.rs

@@ -1,6 +1,7 @@
 use crate::backend::Backend;
 use crate::cmd::get::Get;
 use crate::cmd::hget::HGet;
+use crate::cmd::hgetall::HGetAll;
 use crate::cmd::hset::HSet;
 use crate::cmd::set::Set;
 use crate::{RespArray, RespFrame, RespNull};
@@ -10,6 +11,7 @@ use thiserror::Error;
 
 mod get;
 mod hget;
+mod hgetall;
 mod hset;
 mod set;
 
@@ -29,7 +31,7 @@ pub enum Command {
     Set(Set),
     HGet(HGet),
     HSet(HSet),
-    // HSetAll(hset_all::HSetAll),
+    HSetAll(HGetAll),
     Unrecognized(Unrecognized),
 }
 
@@ -71,7 +73,7 @@ impl TryFrom<RespFrame> for Command {
                 b"set" => Ok(Command::Set(Set::try_from(frame)?)),
                 b"hget" => Ok(Command::HGet(HGet::try_from(frame)?)),
                 b"hset" => Ok(Command::HSet(HSet::try_from(frame)?)),
-                // b"hset_all" => Ok(Command::HSetAll(hset_all::HSetAll::new(cmd))),
+                b"hgetall" => Ok(Command::HSetAll(HGetAll::try_from(frame)?)),
                 _ => Ok(Command::Unrecognized(Unrecognized)),
             },
             _ => Err(CommandError::InvalidArgs("Invalid arguments".to_string())),

src/resp/bulk_string.rs

@@ -31,6 +31,18 @@ impl RespDecode for BulkString {
     }
 }
 
+impl From<String> for BulkString {
+    fn from(s: String) -> Self {
+        BulkString::new(s.into_bytes())
+    }
+}
+
+impl From<&str> for BulkString {
+    fn from(s: &str) -> Self {
+        BulkString::new(s.as_bytes())
+    }
+}
+
 impl From<&[u8]> for BulkString {
     fn from(data: &[u8]) -> Self {
         BulkString(data.to_vec())