Add branch hints to parser

server/src/queryengine/parser.rs

@@ -29,6 +29,7 @@ use crate::corestore::memstore::ObjectID;
 use crate::kvengine::encoding;
 use crate::protocol::responses;
 use crate::queryengine::ActionIter;
+use crate::util::compiler;
 use crate::util::Unwrappable;
 use bytes::Bytes;
 use core::str;
@@ -41,19 +42,25 @@ const STR: &[u8] = "str".as_bytes();
 pub(super) static VALID_CONTAINER_NAME: Lazy<Regex, fn() -> Regex> =
     Lazy::new(|| Regex::new("^[a-zA-Z_$][a-zA-Z_$0-9]*$").unwrap());
 
+#[cold]
+#[inline(never)]
+fn cold_err<T>(v: T) -> T {
+    v
+}
+
 pub(super) fn parse_table_args(mut act: ActionIter) -> Result<(ObjectID, u8), &'static [u8]> {
     let table_name = unsafe { act.next().unsafe_unwrap() };
     let model_name = unsafe { act.next().unsafe_unwrap() };
-    if !encoding::is_utf8(&table_name) || !encoding::is_utf8(&model_name) {
+    if compiler::unlikely(!encoding::is_utf8(&table_name) || !encoding::is_utf8(&model_name)) {
         return Err(responses::groups::ENCODING_ERROR);
     }
     let table_name_str = unsafe { str::from_utf8_unchecked(&table_name) };
     let model_name_str = unsafe { str::from_utf8_unchecked(&model_name) };
-    if !VALID_CONTAINER_NAME.is_match(table_name_str) {
+    if compiler::unlikely(!VALID_CONTAINER_NAME.is_match(table_name_str)) {
         return Err(responses::groups::BAD_EXPRESSION);
     }
     let splits: Vec<&str> = model_name_str.split('(').collect();
-    if splits.len() != 2 {
+    if compiler::unlikely(splits.len() != 2) {
         return Err(responses::groups::BAD_EXPRESSION);
     }
     let model_name_split = unsafe { splits.get_unchecked(0) };
@@ -61,7 +68,7 @@ pub(super) fn parse_table_args(mut act: ActionIter) -> Result<(ObjectID, u8), &'
 
     // model name has to have at least one char while model args should have
     // atleast `)` 1 chars (for example if the model takes no arguments: `smh()`)
-    if model_name_split.is_empty() || model_args_split.is_empty() {
+    if compiler::unlikely(model_name_split.is_empty() || model_args_split.is_empty()) {
         return Err(responses::groups::BAD_EXPRESSION);
     }
 
@@ -77,7 +84,7 @@ pub(super) fn parse_table_args(mut act: ActionIter) -> Result<(ObjectID, u8), &'
             != b')'
     };
 
-    if non_bracketed_end {
+    if compiler::unlikely(non_bracketed_end) {
         return Err(responses::groups::BAD_EXPRESSION);
     }
 
@@ -86,21 +93,25 @@ pub(super) fn parse_table_args(mut act: ActionIter) -> Result<(ObjectID, u8), &'
         .split(',')
         .map(|v| v.trim())
         .collect();
-    if model_args.len() != 2 {
+    if compiler::unlikely(model_args.len() != 2) {
         // nope, someone had fun with commas or they added more args
         // let's check if it was comma fun or if it was arg fun
+        return cold_err({
             let all_nonzero = model_args.into_iter().all(|v| !v.is_empty());
             if all_nonzero {
                 // arg fun
-            return Err(responses::groups::TOO_MANY_ARGUMENTS);
+                Err(responses::groups::TOO_MANY_ARGUMENTS)
             } else {
                 // comma fun
-            return Err(responses::groups::BAD_EXPRESSION);
+                Err(responses::groups::BAD_EXPRESSION)
             }
+        });
     }
     let key_ty = unsafe { model_args.get_unchecked(0) };
     let val_ty = unsafe { model_args.get_unchecked(1) };
-    if !VALID_CONTAINER_NAME.is_match(key_ty) || !VALID_CONTAINER_NAME.is_match(val_ty) {
+    if compiler::unlikely(
+        !VALID_CONTAINER_NAME.is_match(key_ty) || !VALID_CONTAINER_NAME.is_match(val_ty),
+    ) {
         return Err(responses::groups::BAD_EXPRESSION);
     }
     let key_ty = key_ty.as_bytes();
@@ -113,11 +124,11 @@ pub(super) fn parse_table_args(mut act: ActionIter) -> Result<(ObjectID, u8), &'
         _ => return Err(responses::groups::UNKNOWN_DATA_TYPE),
     };
 
-    if table_name_str.len() > 64 {
-        return Err(responses::groups::CONTAINER_NAME_TOO_LONG);
-    }
-
+    if compiler::unlikely(table_name_str.len() > 64) {
+        Err(responses::groups::CONTAINER_NAME_TOO_LONG)
+    } else {
         Ok((unsafe { ObjectID::from_slice(table_name_str) }, model_code))
+    }
 }
 
 pub type EntityGroup<'a> = (Option<&'a [u8]>, Option<&'a [u8]>);
@@ -128,7 +139,7 @@ pub(super) fn get_query_entity<'a>(input: &'a Bytes) -> Result<EntityGroup<'a>,
         if y.len() == 1 {
             // just tbl
             let tblret = y.get_unchecked(0);
-            if tblret.len() > 64 || tblret.is_empty() {
+            if compiler::unlikely(tblret.len() > 64 || tblret.is_empty()) {
                 Err(responses::groups::BAD_CONTAINER_NAME)
             } else {
                 Ok((None, Some(tblret)))
@@ -137,16 +148,16 @@ pub(super) fn get_query_entity<'a>(input: &'a Bytes) -> Result<EntityGroup<'a>,
             // tbl + ns
             let ksret = y.get_unchecked(0);
             let tblret = y.get_unchecked(1);
-            if ksret.len() > 64 || tblret.len() > 64 {
+            if compiler::unlikely(ksret.len() > 64 || tblret.len() > 64) {
                 Err(responses::groups::BAD_CONTAINER_NAME)
-            } else if tblret.is_empty() || ksret.is_empty() {
+            } else if compiler::unlikely(tblret.is_empty() || ksret.is_empty()) {
                 Err(responses::groups::BAD_EXPRESSION)
             } else {
                 Ok((Some(ksret), Some(tblret)))
             }
         } else {
             // something wrong
-            Err(responses::groups::BAD_EXPRESSION)
+            cold_err(Err(responses::groups::BAD_EXPRESSION))
         }
     }
 }