Merge pull request #20 from RedisLabsModules/strlen

Add support for str_len

Author: gkorland

src/lib.rs

@@ -15,7 +15,7 @@ fn json_set(ctx: &Context, args: Vec<String>) -> RedisResult {
     let mut args = args.into_iter().skip(1);
 
     let key = args.next_string()?;
-      let value = args.next_string()?;
+    let value = args.next_string()?;
 
     let key = ctx.open_key_writable(&key);
 
@@ -40,22 +40,37 @@ fn json_get(ctx: &Context, args: Vec<String>) -> RedisResult {
     let key = ctx.open_key_writable(&key);
 
     let value = match key.get_value::<RedisJSON>(&REDIS_JSON_TYPE)? {
-        Some(doc) => { doc.to_string(&path)?.into() }
+        Some(doc) => doc.to_string(&path)?.into(),
         None => ().into()
     };
 
     Ok(value)
 }
 
-fn json_type(ctx: &Context, args: Vec<String>) -> RedisResult {
+fn json_strlen(ctx: &Context, args: Vec<String>) -> RedisResult {
     let mut args = args.into_iter().skip(1);
     let key = args.next_string()?;
     let path = args.next_string()?;
+  
+    let key = ctx.open_key_writable(&key);  
+  
+    let length = match key.get_value::<RedisJSON>(&REDIS_JSON_TYPE)? {
+        Some(doc) => doc.str_len(&path)?.into(),
+        None => ().into()
+    };
+
+    Ok(length)
+}
 
+fn json_type(ctx: &Context, args: Vec<String>) -> RedisResult {
+    let mut args = args.into_iter().skip(1);
+    let key = args.next_string()?;
+    let path = args.next_string()?;
+  
     let key = ctx.open_key_writable(&key);
 
     let value = match key.get_value::<RedisJSON>(&REDIS_JSON_TYPE)? {
-        Some(doc) => { doc.get_type(&path)?.into() }
+        Some(doc) => doc.get_type(&path)?.into(),
         None => ().into()
     };
 
@@ -73,6 +88,7 @@ redis_module! {
     commands: [
         ["json.set", json_set, "write"],
         ["json.get", json_get, ""],
+        ["json.strlen", json_strlen, ""],
         ["json.type", json_type, ""],
     ],
 }

src/redisjson.rs

@@ -52,17 +52,24 @@ impl RedisJSON {
     pub fn to_string(&self, path: &str) -> Result<String, Error> {
         eprintln!("Serializing back to JSON");
 
-        // Create a JSONPath selector
-        let selector = Selector::new(path).map_err(|e| Error {
-            msg: format!("{}", e),
-        })?;
-
-        let s = match selector.find(&self.data).next() {
+        let s = match self.get_doc(path)? {
             Some(doc) => serde_json::to_string(&doc)?,
             None => String::new()
         };
 
-        return Ok(s)
+        Ok(s)
+    }
+
+    pub fn str_len(&self, path: &str) -> Result<usize, Error> {
+        match self.get_doc(path)? {
+            Some(doc) => {
+                match doc.as_str() {
+                    Some(s) => Ok(s.len()),
+                    None => Err(Error{msg: "ERR wrong type of path value".to_string()})
+                }
+            }
+            None => Ok(0) // path not found
+        }
     }
 
     pub fn get_type(&self, path: &str) -> Result<String, Error> {