[Query] Support Description about Graph Space (#388)

* support describe space

* support describe space

* support desc space

* address dangleptr's comment

* address dutor's comment

* using async

* address dangleptr's comment

* fix

* fix copyright

* address dangleptr's comment

* fix

* fix

src/executor/CMakeLists.txt

@@ -31,6 +31,7 @@ add_library(
     RemoveHostsExecutor.cpp
     CreateSpaceExecutor.cpp
     DropSpaceExecutor.cpp
+    DescribeSpaceExecutor.cpp
     ShowExecutor.cpp
     YieldExecutor.cpp
 )

src/executor/DescribeEdgeExecutor.cpp

@@ -28,28 +28,25 @@ void DescribeEdgeExecutor::execute() {
     auto edgeType = ectx()->schemaManager()->toEdgeType(spaceId, *name);
     auto schema = ectx()->schemaManager()->getEdgeSchema(spaceId, edgeType);
     resp_ = std::make_unique<cpp2::ExecutionResponse>();
-
-    do {
-        if (schema == nullptr) {
-            onError_(Status::Error("Schema not found for edge `%s'", name->c_str()));
-            return;
-        }
-        std::vector<std::string> header{"Field", "Type"};
-        resp_->set_column_names(std::move(header));
-        uint32_t numFields = schema->getNumFields();
-        std::vector<cpp2::RowValue> rows;
-        for (uint32_t index = 0; index < numFields; index++) {
-            std::vector<cpp2::ColumnValue> row;
-            row.resize(2);
-            row[0].set_str(schema->getFieldName(index));
-            row[1].set_str(valueTypeToString(schema->getFieldType(index)));
-            rows.emplace_back();
-            rows.back().set_columns(std::move(row));
-        }
-
-        resp_->set_rows(std::move(rows));
-    } while (false);
-
+    if (schema == nullptr) {
+        onError_(Status::Error("Schema not found for edge `%s'", name->c_str()));
+        return;
+    }
+
+    std::vector<std::string> header{"Field", "Type"};
+    resp_->set_column_names(std::move(header));
+    uint32_t numFields = schema->getNumFields();
+    std::vector<cpp2::RowValue> rows;
+    for (uint32_t index = 0; index < numFields; index++) {
+        std::vector<cpp2::ColumnValue> row;
+        row.resize(2);
+        row[0].set_str(schema->getFieldName(index));
+        row[1].set_str(valueTypeToString(schema->getFieldType(index)));
+        rows.emplace_back();
+        rows.back().set_columns(std::move(row));
+    }
+
+    resp_->set_rows(std::move(rows));
     DCHECK(onFinish_);
     onFinish_();
 }

src/executor/DescribeSpaceExecutor.cpp

+/* Copyright (c) 2019 - present, VE Software Inc. All rights reserved
+ *
+ * This source code is licensed under Apache 2.0 License
+ *  (found in the LICENSE.Apache file in the root directory)
+ */
+
+#include "base/Base.h"
+#include "graph/DescribeSpaceExecutor.h"
+#include "meta/SchemaManager.h"
+
+namespace nebula {
+namespace graph {
+
+DescribeSpaceExecutor::DescribeSpaceExecutor(Sentence *sentence,
+                                             ExecutionContext *ectx) : Executor(ectx) {
+    sentence_ = static_cast<DescribeSpaceSentence*>(sentence);
+}
+
+Status DescribeSpaceExecutor::prepare() {
+    return Status::OK();;
+}
+
+void DescribeSpaceExecutor::execute() {
+    auto *name = sentence_->spaceName();
+    auto spaceId = ectx()->schemaManager()->toGraphSpaceID(*name);
+    auto future = ectx()->getMetaClient()->getSpace(spaceId);
+    auto *runner = ectx()->rctx()->runner();
+
+    auto cb = [this] (auto &&resp) {
+      if (!resp.ok()) {
+        onError_(Status::Error("Space not found"));
+        return;
+      }
+
+      resp_ = std::make_unique<cpp2::ExecutionResponse>();
+      std::vector<std::string> header{"ID", "Name", "Partition number", "Replica Factor"};
+      resp_->set_column_names(std::move(header));
+
+      std::vector<cpp2::RowValue> rows;
+      std::vector<cpp2::ColumnValue> row;
+      row.resize(4);
+      row[0].set_integer(resp.value().get_space_id());
+
+      auto properties = resp.value().get_properties();
+      row[1].set_str(properties.get_space_name());
+      row[2].set_integer(properties.get_partition_num());
+      row[3].set_integer(properties.get_replica_factor());
+
+      rows.emplace_back();
+      rows.back().set_columns(std::move(row));
+      resp_->set_rows(std::move(rows));
+      DCHECK(onFinish_);
+      onFinish_();
+    };
+
+    auto error = [this] (auto &&e) {
+        LOG(ERROR) << "Exception caught: " << e.what();
+        DCHECK(onError_);
+        onError_(Status::Error("Internal error"));
+        return;
+    };
+
+    std::move(future).via(runner).thenValue(cb).thenError(error);
+}
+
+void DescribeSpaceExecutor::setupResponse(cpp2::ExecutionResponse &resp) {
+    resp = std::move(*resp_);
+}
+
+}   // namespace graph
+}   // namespace nebula

src/executor/DescribeSpaceExecutor.h

+/* Copyright (c) 2019 - present, VE Software Inc. All rights reserved
+ *
+ * This source code is licensed under Apache 2.0 License
+ *  (found in the LICENSE.Apache file in the root directory)
+ */
+
+#ifndef GRAPH_DESCRIBESPACEEXECUTOR_H_
+#define GRAPH_DESCRIBESPACEEXECUTOR_H_
+
+#include "base/Base.h"
+#include "graph/Executor.h"
+
+namespace nebula {
+namespace graph {
+
+class DescribeSpaceExecutor final : public Executor {
+public:
+    DescribeSpaceExecutor(Sentence *sentence, ExecutionContext *ectx);
+
+    const char* name() const override {
+        return "DescribeSpaceExecutor";
+    }
+
+    Status MUST_USE_RESULT prepare() override;
+
+    void execute() override;
+
+    void setupResponse(cpp2::ExecutionResponse &resp) override;
+
+private:
+    DescribeSpaceSentence                      *sentence_{nullptr};
+    std::string                                *tag_{nullptr};
+    std::unique_ptr<cpp2::ExecutionResponse>    resp_;
+};
+
+}   // namespace graph
+}   // namespace nebula
+
+#endif  // GRAPH_DESCRIBESPACEEXECUTOR_H_

src/executor/DescribeTagExecutor.cpp

@@ -29,28 +29,25 @@ void DescribeTagExecutor::execute() {
     auto schema = ectx()->schemaManager()->getTagSchema(spaceId, tagId);
 
     resp_ = std::make_unique<cpp2::ExecutionResponse>();
-
-    do {
-        if (schema == nullptr) {
-            onError_(Status::Error("Schema not found for tag `%s'", name->c_str()));
-            return;
-        }
-        std::vector<std::string> header{"Field", "Type"};
-        resp_->set_column_names(std::move(header));
-        uint32_t numFields = schema->getNumFields();
-        std::vector<cpp2::RowValue> rows;
-        for (uint32_t index = 0; index < numFields; index++) {
-            std::vector<cpp2::ColumnValue> row;
-            row.resize(2);
-            row[0].set_str(schema->getFieldName(index));
-            row[1].set_str(valueTypeToString(schema->getFieldType(index)));
-            rows.emplace_back();
-            rows.back().set_columns(std::move(row));
-        }
-
-        resp_->set_rows(std::move(rows));
-    } while (false);
-
+    if (schema == nullptr) {
+        onError_(Status::Error("Schema not found for tag `%s'", name->c_str()));
+        return;
+    }
+
+    std::vector<std::string> header{"Field", "Type"};
+    resp_->set_column_names(std::move(header));
+    uint32_t numFields = schema->getNumFields();
+    std::vector<cpp2::RowValue> rows;
+    for (uint32_t index = 0; index < numFields; index++) {
+        std::vector<cpp2::ColumnValue> row;
+        row.resize(2);
+        row[0].set_str(schema->getFieldName(index));
+        row[1].set_str(valueTypeToString(schema->getFieldType(index)));
+        rows.emplace_back();
+        rows.back().set_columns(std::move(row));
+    }
+
+    resp_->set_rows(std::move(rows));
     DCHECK(onFinish_);
     onFinish_();
 }

src/executor/Executor.cpp

@@ -28,6 +28,7 @@
 #include "graph/AddHostsExecutor.h"
 #include "graph/RemoveHostsExecutor.h"
 #include "graph/CreateSpaceExecutor.h"
+#include "graph/DescribeSpaceExecutor.h"
 #include "graph/DropSpaceExecutor.h"
 #include "graph/YieldExecutor.h"
 
@@ -95,6 +96,9 @@ std::unique_ptr<Executor> Executor::makeExecutor(Sentence *sentence) {
         case Sentence::Kind::kDropSpace:
             executor = std::make_unique<DropSpaceExecutor>(sentence, ectx());
             break;
+        case Sentence::Kind::kDescribeSpace:
+            executor = std::make_unique<DescribeSpaceExecutor>(sentence, ectx());
+            break;
         case Sentence::Kind::kYield:
             executor = std::make_unique<YieldExecutor>(sentence, ectx());
             break;

src/executor/test/GraphHttpHandlerTest.cpp

-/* Copyright (c) 2018 vesoft inc. All rights reserved.
+/* Copyright (c) 2019 vesoft inc. All rights reserved.
  *
  * This source code is licensed under Apache 2.0 License,
  * attached with Common Clause Condition 1.0, found in the LICENSES directory.

src/executor/test/SchemaTest.cpp

@@ -59,6 +59,17 @@ TEST_F(SchemaTest, metaCommunication) {
         ASSERT_EQ(cpp2::ErrorCode::SUCCEEDED, code);
     }
     sleep(FLAGS_load_data_interval_secs + 1);
+    {
+        cpp2::ExecutionResponse resp;
+        std::string query = "DESCRIBE SPACE default_space";
+        auto code = client->execute(query, resp);
+        ASSERT_EQ(cpp2::ErrorCode::SUCCEEDED, code);
+        std::vector<std::tuple<int, std::string, int, int>> expected{
+            {1, "default_space", 9, 3},
+        };
+        ASSERT_TRUE(verifyResult(resp, expected));
+    }
+    sleep(FLAGS_load_data_interval_secs + 1);
     {
         cpp2::ExecutionResponse resp;
         std::string query = "USE default_space";

src/parser/AdminSentences.cpp

@@ -49,25 +49,13 @@ std::string HostList::toString() const {
 
 
 std::string AddHostsSentence::toString() const {
-    std::string buf;
-    buf.reserve(256);
-    buf += "ADD HOSTS (";
-    buf += hosts_->toString();
-    buf += ") ";
-    return buf;
+    return folly::stringPrintf("ADD HOSTS (%s) ", hosts_->toString().c_str());
 }
 
-
 std::string RemoveHostsSentence::toString() const {
-    std::string buf;
-    buf.reserve(256);
-    buf += "REMOVE HOSTS (";
-    buf += hosts_->toString();
-    buf += ") ";
-    return buf;
+    return folly::stringPrintf("REMOVE HOSTS (%s) ", hosts_->toString().c_str());
 }
 
-
 std::string SpaceOptItem::toString() const {
     switch (optType_) {
         case PARTITION_NUM:
@@ -96,23 +84,16 @@ std::string SpaceOptList::toString() const {
 
 
 std::string CreateSpaceSentence::toString() const {
-    std::string buf;
-    buf.reserve(256);
-    buf += "CREATE SPACE ";
-    buf += *spaceName_;
-    buf += "(";
-    buf += spaceOpts_->toString();
-    buf += ") ";
-    return buf;
+    return folly::stringPrintf("CREATE SPACE  %s(%s) ", spaceName_.get()->c_str(),
+                               spaceOpts_->toString().c_str());
 }
 
-
 std::string DropSpaceSentence::toString() const {
-    std::string buf;
-    buf.reserve(256);
-    buf += "DROP SPACE ";
-    buf += *spaceName_;
-    return buf;
+    return folly::stringPrintf("DROP SPACE  %s", spaceName_.get()->c_str());
+}
+
+std::string DescribeSpaceSentence::toString() const {
+    return folly::stringPrintf("DESCRIBE SPACE  %s", spaceName_.get()->c_str());
 }
 
 }   // namespace nebula

src/parser/AdminSentences.h

@@ -6,7 +6,6 @@
 #ifndef PARSER_ADMINSENTENCES_H_
 #define PARSER_ADMINSENTENCES_H_
 
-#include "base/Base.h"
 #include "parser/Clauses.h"
 #include "parser/Sentence.h"
 #include "network/NetworkUtils.h"
@@ -251,6 +250,24 @@ private:
     std::unique_ptr<std::string>     spaceName_;
 };
 
+
+class DescribeSpaceSentence final : public Sentence {
+public:
+    explicit DescribeSpaceSentence(std::string *spaceName) {
+        spaceName_.reset(spaceName);
+        kind_ = Kind::kDescribeSpace;
+    }
+
+    std::string* spaceName() {
+        return spaceName_.get();
+    }
+
+    std::string toString() const override;
+
+private:
+    std::unique_ptr<std::string>     spaceName_;
+};
+
 }   // namespace nebula
 
 #endif  // PARSER_ADMINSENTENCES_H_

src/parser/Sentence.h

@@ -42,6 +42,7 @@ public:
         kRemoveHosts,
         kCreateSpace,
         kDropSpace,
+        kDescribeSpace,
         kYield,
         kCreateUser,
         kDropUser,

src/parser/parser.yy

@@ -156,7 +156,7 @@ class GraphScanner;
 %type <sentence> traverse_sentence set_sentence piped_sentence assignment_sentence
 %type <sentence> maintain_sentence insert_vertex_sentence insert_edge_sentence
 %type <sentence> mutate_sentence update_vertex_sentence update_edge_sentence delete_vertex_sentence delete_edge_sentence
-%type <sentence> show_sentence add_hosts_sentence remove_hosts_sentence create_space_sentence
+%type <sentence> show_sentence add_hosts_sentence remove_hosts_sentence create_space_sentence describe_space_sentence
 %type <sentence> drop_space_sentence
 %type <sentence> yield_sentence
 %type <sentence> create_user_sentence alter_user_sentence drop_user_sentence change_password_sentence
@@ -937,6 +937,12 @@ create_space_sentence
     }
     ;
 
+describe_space_sentence
+    : KW_DESCRIBE KW_SPACE LABEL {
+        $$ = new DescribeSpaceSentence($3);
+    }
+    ;
+
 space_opt_list
     : space_opt_item {
         $$ = new SpaceOptList();
@@ -1105,6 +1111,7 @@ maintain_sentence
     | add_hosts_sentence { $$ = $1; }
     | remove_hosts_sentence { $$ = $1; }
     | create_space_sentence { $$ = $1; }
+    | describe_space_sentence { $$ = $1; }
     | drop_space_sentence { $$ = $1; }
     | yield_sentence {
         // Now we take YIELD as a normal maintenance sentence.