fixed fixed_string expression eval for go (vesoft-inc#74)

Co-authored-by: bright-starry-sky <56461666+bright-starry-sky@users.noreply.github.com>

src/storage/context/StorageExpressionContext.cpp

@@ -9,6 +9,7 @@
 #include "common/utils/DefaultValueContext.h"
 #include "common/utils/IndexKeyUtils.h"
 #include "common/utils/NebulaKeyUtils.h"
+#include "storage/exec/QueryUtils.h"
 
 namespace nebula {
 namespace storage {
@@ -17,22 +18,13 @@ Value StorageExpressionContext::readValue(const std::string& propName) const {
   if (!schema_) {
     return Value::kNullValue;
   }
-  auto field = schema_->field(propName);
-  if (!field) {
-    return Value::kNullValue;
-  }
-  auto value = reader_->getValueByName(propName);
-  if (value.type() == Value::Type::NULLVALUE) {
-    // read null value
-    auto nullType = value.getNull();
-    if (nullType == NullType::UNKNOWN_PROP && field->hasDefault()) {
-      DefaultValueContext expCtx;
-      auto expr = field->defaultValue()->clone();
-      return Value(Expression::eval(expr, expCtx));
-    }
+
+  auto ret = QueryUtils::readValue(reader_, propName, schema_);
+  if (!ret.ok()) {
     return Value::kNullValue;
   }
-  return value;
+
+  return std::move(ret).value();
 }
 
 // Get the specified property from the tag, such as tag_name.prop_name
@@ -120,12 +112,12 @@ Value StorageExpressionContext::getSrcProp(const std::string& tagName,
 }
 
 Value StorageExpressionContext::getIndexValue(const std::string& prop, bool isEdge) const {
-  // TODO (sky) : Handle string type values.
-  //              when field type is FIXED_STRING type,
-  //              actual length of the value is called "len"
-  //              FIXED_STRING.type.len is called "fixed_len"
-  //              if (len > fixed_len) : v = value.substr(0, fixed_len)
-  //              if (len < fixed_len) : v.append(fixed_len - len, '\0')
+  // Handle string type values.
+  // when field type is FIXED_STRING type,
+  // actual length of the value is called "len"
+  // FIXED_STRING.type.len is called "fixed_len"
+  // if (len > fixed_len) : v = value.substr(0, fixed_len)
+  // if (len < fixed_len) : v.append(fixed_len - len, '\0')
   return IndexKeyUtils::getValueFromIndexKey(vIdLen_, key_, prop, fields_, isEdge, hasNullableCol_);
 }
 

src/storage/exec/QueryUtils.h

@@ -71,6 +71,10 @@ class QueryUtils final {
       }
       return Status::Error(folly::stringPrintf("Fail to read prop %s ", propName.c_str()));
     }
+    if (field->type() == meta::cpp2::PropertyType::FIXED_STRING) {
+      const auto& fixedStr = value.getStr();
+      return fixedStr.substr(0, fixedStr.find_first_of('\0'));
+    }
     return value;
   }
 

tests/tck/features/expression/FixedString.feature

@@ -0,0 +1,54 @@
+Feature: FixedString expression Eval
+
+  Scenario: FixedString GO Expression
+    Given an empty graph
+    And create a space with following options:
+      | partition_num  | 1        |
+      | replica_factor | 1        |
+      | vid_type       | int64    |
+      | charset        | utf8     |
+      | collate        | utf8_bin |
+    And having executed:
+      """
+      CREATE TAG IF NOT EXISTS fixed_string_tag_1(c1 fixed_string(30));
+      CREATE EDGE IF NOT EXISTS fixed_string_edge_1(c1 fixed_string(30));
+      """
+    # insert vertex succeeded
+    When try to execute query:
+      """
+      INSERT VERTEX fixed_string_tag_1(c1) VALUES 1:("row"), 2:("row"), 3:("row")
+      """
+    Then the execution should be successful
+    # insert edge succeeded
+    When executing query:
+      """
+      INSERT EDGE fixed_string_edge_1(c1) VALUES 1->2:("row"), 1->3:("row")
+      """
+    Then the execution should be successful
+    # check fixed string expression with go
+    When executing query:
+      """
+      GO from 1 over fixed_string_edge_1 where $$.fixed_string_tag_1.c1 == "row" yield $$.fixed_string_tag_1.c1 as c1
+      """
+    Then the result should be, in any order, with relax comparison:
+      | c1    |
+      | "row" |
+      | "row" |
+    # check fixed string expression with go
+    When executing query:
+      """
+      GO from 1 over fixed_string_edge_1 where $^.fixed_string_tag_1.c1 == "row" yield $$.fixed_string_tag_1.c1 as c1
+      """
+    Then the result should be, in any order, with relax comparison:
+      | c1    |
+      | "row" |
+      | "row" |
+    # check fixed string expression with go
+    When executing query:
+      """
+      GO from 1 over fixed_string_edge_1 where fixed_string_edge_1.c1 == "row" yield $$.fixed_string_tag_1.c1 as c1
+      """
+    Then the result should be, in any order, with relax comparison:
+      | c1    |
+      | "row" |
+      | "row" |