chore: add namespace for client side statements in PostgreSQL dialect

README.md

@@ -56,13 +56,13 @@ implementation 'com.google.cloud:google-cloud-spanner'
 If you are using Gradle without BOM, add this to your dependencies
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-spanner:6.21.1'
+implementation 'com.google.cloud:google-cloud-spanner:6.21.2'
 ```
 
 If you are using SBT, add this to your dependencies
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.21.1"
+libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.21.2"
 ```
 
 ## Authentication

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/AbstractStatementParser.java

@@ -22,13 +22,11 @@
 import com.google.cloud.spanner.SpannerException;
 import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.cloud.spanner.Statement;
-import com.google.cloud.spanner.connection.ClientSideStatementImpl.CompileException;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.spanner.v1.ExecuteSqlRequest.QueryOptions;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -322,14 +320,9 @@ ClientSideStatement getClientSideStatement() {
   private final Dialect dialect;
   private final Set<ClientSideStatementImpl> statements;
 
-  AbstractStatementParser(Dialect dialect) {
+  AbstractStatementParser(Dialect dialect, Set<ClientSideStatementImpl> statements) {
     this.dialect = dialect;
-    try {
-      statements =
-          Collections.unmodifiableSet(ClientSideStatements.INSTANCE.getCompiledStatements());
-    } catch (CompileException e) {
-      throw new RuntimeException(e);
-    }
+    this.statements = statements;
   }
 
   /**

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ClientSideStatementPgBeginExecutor.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.spanner.connection;
+
+import com.google.cloud.spanner.ErrorCode;
+import com.google.cloud.spanner.SpannerExceptionFactory;
+import com.google.cloud.spanner.connection.ClientSideStatementImpl.CompileException;
+import com.google.cloud.spanner.connection.ClientSideStatementValueConverters.PgTransactionModeConverter;
+import java.lang.reflect.Method;
+import java.util.regex.Matcher;
+
+/** Specific executor for the BEGIN statement for PostgreSQL. */
+class ClientSideStatementPgBeginExecutor implements ClientSideStatementExecutor {
+  private final ClientSideStatementImpl statement;
+  private final Method method;
+  private final PgTransactionModeConverter converter;
+
+  ClientSideStatementPgBeginExecutor(ClientSideStatementImpl statement) throws CompileException {
+    try {
+      this.statement = statement;
+      this.converter = new PgTransactionModeConverter();
+      this.method =
+          ConnectionStatementExecutor.class.getDeclaredMethod(
+              statement.getMethodName(), converter.getParameterClass());
+    } catch (Exception e) {
+      throw new CompileException(e, statement);
+    }
+  }
+
+  @Override
+  public StatementResult execute(ConnectionStatementExecutor connection, String sql)
+      throws Exception {
+    return (StatementResult) method.invoke(connection, getParameterValue(sql));
+  }
+
+  PgTransactionMode getParameterValue(String sql) {
+    Matcher matcher = statement.getPattern().matcher(sql);
+    if (matcher.find() && matcher.groupCount() >= 1) {
+      String value = matcher.group(1);
+      if (value != null) {
+        PgTransactionMode res = converter.convert(value.trim());
+        if (res != null) {
+          return res;
+        }
+        throw SpannerExceptionFactory.newSpannerException(
+            ErrorCode.INVALID_ARGUMENT, String.format("Unknown transaction mode: %s", value));
+      }
+    }
+    return null;
+  }
+}

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ClientSideStatementValueConverters.java

@@ -29,6 +29,7 @@
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -121,6 +122,48 @@ public Duration convert(String value) {
     }
   }
 
+  /** Converter from string to {@link Duration}. */
+  static class PgDurationConverter implements ClientSideStatementValueConverter<Duration> {
+    private final Pattern allowedValues;
+
+    public PgDurationConverter(String allowedValues) {
+      // Remove the parentheses from the beginning and end.
+      this.allowedValues =
+          Pattern.compile(
+              "(?is)\\A" + allowedValues.substring(1, allowedValues.length() - 1) + "\\z");
+    }
+
+    @Override
+    public Class<Duration> getParameterClass() {
+      return Duration.class;
+    }
+
+    @Override
+    public Duration convert(String value) {
+      Matcher matcher = allowedValues.matcher(value);
+      if (matcher.find()) {
+        Duration duration;
+        if (matcher.group(0).equalsIgnoreCase("default")) {
+          return Durations.fromNanos(0L);
+        } else if (matcher.group(2) == null) {
+          duration =
+              ReadOnlyStalenessUtil.createDuration(
+                  Long.parseLong(matcher.group(0)), TimeUnit.MILLISECONDS);
+        } else {
+          duration =
+              ReadOnlyStalenessUtil.createDuration(
+                  Long.parseLong(matcher.group(1)),
+                  ReadOnlyStalenessUtil.parseTimeUnit(matcher.group(2)));
+        }
+        if (duration.getSeconds() == 0L && duration.getNanos() == 0) {
+          return null;
+        }
+        return duration;
+      }
+      return null;
+    }
+  }
+
   /** Converter from string to possible values for read only staleness ({@link TimestampBound}). */
   static class ReadOnlyStalenessConverter
       implements ClientSideStatementValueConverter<TimestampBound> {
@@ -243,6 +286,33 @@ public TransactionMode convert(String value) {
     }
   }
 
+  /**
+   * Converter for converting string values to {@link PgTransactionMode} values. Includes no-op
+   * handling of setting the isolation level of the transaction to default or serializable.
+   */
+  static class PgTransactionModeConverter
+      implements ClientSideStatementValueConverter<PgTransactionMode> {
+    private final CaseInsensitiveEnumMap<PgTransactionMode> values =
+        new CaseInsensitiveEnumMap<>(
+            PgTransactionMode.class, PgTransactionMode::getStatementString);
+
+    PgTransactionModeConverter() {}
+
+    public PgTransactionModeConverter(String allowedValues) {}
+
+    @Override
+    public Class<PgTransactionMode> getParameterClass() {
+      return PgTransactionMode.class;
+    }
+
+    @Override
+    public PgTransactionMode convert(String value) {
+      // Transaction mode may contain multiple spaces.
+      String valueWithSingleSpaces = value.replaceAll("\\s+", " ");
+      return values.get(valueWithSingleSpaces);
+    }
+  }
+
   /** Converter for converting strings to {@link RpcPriority} values. */
   static class RpcPriorityConverter implements ClientSideStatementValueConverter<Priority> {
     private final CaseInsensitiveEnumMap<Priority> values =

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ClientSideStatements.java

@@ -16,6 +16,9 @@
 
 package com.google.cloud.spanner.connection;
 
+import com.google.cloud.spanner.Dialect;
+import com.google.cloud.spanner.ErrorCode;
+import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.cloud.spanner.connection.ClientSideStatementImpl.CompileException;
 import com.google.gson.Gson;
 import java.io.InputStreamReader;
@@ -24,7 +27,21 @@
 /** This class reads and parses the {@link ClientSideStatement}s from the json file. */
 class ClientSideStatements {
   private static final String STATEMENTS_DEFINITION_FILE = "ClientSideStatements.json";
-  static final ClientSideStatements INSTANCE = importStatements();
+  private static final String PG_STATEMENTS_DEFINITION_FILE = "PG_ClientSideStatements.json";
+  private static final ClientSideStatements INSTANCE = importStatements();
+  private static final ClientSideStatements PG_INSTANCE = pgImportStatements();
+
+  static ClientSideStatements getInstance(Dialect dialect) {
+    switch (dialect) {
+      case GOOGLE_STANDARD_SQL:
+        return INSTANCE;
+      case POSTGRESQL:
+        return PG_INSTANCE;
+      default:
+        throw SpannerExceptionFactory.newSpannerException(
+            ErrorCode.INVALID_ARGUMENT, "Unknown or unsupported dialect: " + dialect);
+    }
+  }
 
   /**
    * Reads statement definitions from ClientSideStatements.json and parses these as Java objects.
@@ -37,6 +54,18 @@ private static ClientSideStatements importStatements() {
         ClientSideStatements.class);
   }
 
+  /**
+   * Reads statement definitions from PG_ClientSideStatements.json and parses these as Java objects.
+   */
+  private static ClientSideStatements pgImportStatements() {
+    Gson gson = new Gson();
+    return gson.fromJson(
+        new InputStreamReader(
+            ClientSideStatements.class.getResourceAsStream(PG_STATEMENTS_DEFINITION_FILE)),
+        ClientSideStatements.class);
+  }
+
+  // This field is set automatically by the importStatements / pgImportStatements methods.
   private Set<ClientSideStatementImpl> statements;
 
   private ClientSideStatements() {}

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionStatementExecutor.java

@@ -85,12 +85,19 @@ interface ConnectionStatementExecutor {
 
   StatementResult statementBeginTransaction();
 
+  StatementResult statementBeginPgTransaction(PgTransactionMode transactionMode);
+
   StatementResult statementCommit();
 
   StatementResult statementRollback();
 
   StatementResult statementSetTransactionMode(TransactionMode mode);
 
+  StatementResult statementSetPgTransactionMode(PgTransactionMode transactionMode);
+
+  StatementResult statementSetPgSessionCharacteristicsTransactionMode(
+      PgTransactionMode transactionMode);
+
   StatementResult statementStartBatchDdl();
 
   StatementResult statementStartBatchDml();