Bigtable: Read modify write row model

Bigtable/src/DataClient.php

@@ -21,7 +21,9 @@
 use Google\ApiCore\Serializer;
 use Google\Cloud\Bigtable\Exception\BigtableDataOperationException;
 use Google\Cloud\Bigtable\Filter\FilterInterface;
+use Google\Cloud\Bigtable\ReadModifyWriteRowRules;
 use Google\Cloud\Bigtable\V2\BigtableClient as TableClient;
+use Google\Cloud\Bigtable\V2\Row;
 use Google\Cloud\Bigtable\V2\RowRange;
 use Google\Cloud\Bigtable\V2\RowSet;
 use Google\Cloud\Core\ArrayTrait;
@@ -322,4 +324,83 @@ public function readRow($rowKey, array $options = [])
             ->readAll()
             ->current();
     }
+
+    /**
+     * Modifies a row atomically on the server. The method reads the latest
+     * existing timestamp and value from the specified columns and writes a new
+     * entry based on pre-defined read/modify/write rules. The new value for the
+     * timestamp is the greater of the existing timestamp or the current server
+     * time. The method returns the new contents of all modified cells.
+     *
+     * Example:
+     * ```
+     * use Google\Cloud\Bigtable\ReadModifyWriteRowRules;
+     *
+     * $rules = (new ReadModifyWriteRowRules)
+     *     ->append('cf1', 'cq1', 'value12');
+     * $row = $dataClient->readModifyWriteRow('rk1', $rules);
+     *
+     * print_r($row);
+     * ```
+     *
+     * //Increments value
+     * ```
+     * use Google\Cloud\Bigtable\DataUtil;
+     * use Google\Cloud\Bigtable\ReadModifyWriteRowRules;
+     * use Google\Cloud\Bigtable\RowMutation;
+     *
+     * $rowMutation = new RowMutation('rk1');
+     * $rowMutation->upsert('cf1', 'cq1', DataUtil::intToByteString(2));
+     *
+     * $dataClient->mutateRows([$rowMutation]);
+     *
+     * $rules = (new ReadModifyWriteRowRules)
+     *     ->increment('cf1', 'cq1', 3);
+     * $row = $dataClient->readModifyWriteRow('rk1', $rules);
+     *
+     * print_r($row);
+     * ```
+     *
+     * @param string $rowKey The row key to read.
+     * @param ReadModifyWriteRowRules $rules Rules to apply on row.
+     * @param array $options [optional] Configuration options.
+     * @return array Returns array containing all column family keyed by family name.
+     * @throws ApiException if the remote call fails or operation fails
+     */
+    public function readModifyWriteRow($rowKey, ReadModifyWriteRowRules $rules, array $options = [])
+    {
+        $readModifyWriteRowResponse = $this->bigtableClient->readModifyWriteRow(
+            $this->tableName,
+            $rowKey,
+            $rules->toProto(),
+            $options + $this->options
+        );
+        return $this->convertToArray($readModifyWriteRowResponse->getRow());
+    }
+
+    private function convertToArray(Row $row)
+    {
+        if ($row === null) {
+            return [];
+        }
+        $families = [];
+        foreach ($row->getFamilies() as $family) {
+            $qualifiers = [];
+            foreach ($family->getColumns() as $column) {
+                $values = [];
+                foreach ($column->getCells() as $cell) {
+                    $values[] = [
+                        'value' => $cell->getValue(),
+                        'timeStamp' => $cell->getTimestampMicros(),
+                        'labels' => ($cell->getLabels()->getIterator()->valid())
+                            ? implode(iterator_to_array($cell->getLabels()->getIterator()))
+                            : ''
+                    ];
+                }
+                $qualifiers[$column->getQualifier()] = $values;
+            }
+            $families[$family->getName()] = $qualifiers;
+        }
+        return $families;
+    }
 }

Bigtable/src/DataUtil.php

@@ -0,0 +1,85 @@
+<?php
+/**
+ * Copyright 2018, Google LLC All rights reserved.
+ *
+ * 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.
+ */
+
+namespace Google\Cloud\Bigtable;
+
+/**
+ * This class contains utility to convert integer to byte string and backward.
+ * This utility class is only supported on 64 bit machine with PHP version > 5.5.
+ */
+class DataUtil
+{
+    private static $isLittleEndian;
+    private static $isSupported;
+
+    public static function isSystemLittleEndian()
+    {
+        if (self::$isLittleEndian === null) {
+            self::$isLittleEndian = (pack("P", 2) === pack("Q", 2));
+        }
+        return self::$isLittleEndian;
+    }
+
+    public static function isSupported()
+    {
+        if (self::$isSupported === null) {
+            self::$isSupported = PHP_VERSION_ID > 50500;
+        }
+        return self::$isSupported;
+    }
+
+    /**
+     * Utility method to convert an integer to a 64-bit big-endian signed integer byte string.
+     *
+     * @param int $intValue Integer value to convert to.
+     * @return string Returns a string of bytes representing a 64-bit big-endian signed integer.
+     * @throws \InvalidArgumentException If value is not an integer.
+     */
+    public static function intToByteString($intValue)
+    {
+        if (!self::isSupported()) {
+            throw new \ErrorException('This utility is only supported on 64 bit machine with PHP version > 5.5.');
+        }
+        if (!is_int($intValue)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    'Expected argument to be of type int, instead got \'%s\'.',
+                    gettype($intValue)
+                )
+            );
+        }
+        $bytes = pack("J", $intValue);
+        return $bytes;
+    }
+
+    /**
+     * Converts a 64-bit big-endian signed integer represented as a byte string to an integer.
+     *
+     * @param string $bytes String of bytes to convert.
+     * @return int Integer value of the string bytes.
+     */
+    public static function byteStringToInt($bytes)
+    {
+        if (!self::isSupported()) {
+            throw new \ErrorException('This utility is only supported on 64 bit machine with PHP version > 5.5.');
+        }
+        if (self::isSystemLittleEndian()) {
+            $bytes = strrev($bytes);
+        }
+        return unpack("q", $bytes)[1];
+    }
+}

Bigtable/src/ReadModifyWriteRowRules.php

@@ -0,0 +1,85 @@
+<?php
+/**
+ * Copyright 2018, Google LLC All rights reserved.
+ *
+ * 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.
+ */
+
+namespace Google\Cloud\Bigtable;
+
+use Google\Cloud\Bigtable\V2\ReadModifyWriteRule;
+
+/**
+ * This is a builder class which builds read/modify/write rules specifying how the specified rows contents
+ * are to be transformed into writes. Entries are applied in order, meaning that earlier rules will
+ * affect the results of later ones. This is intended to be used in combination with
+ * {@see Google\Cloud\Bigtable\DataClient::readModifyWriteRow()}.
+ */
+class ReadModifyWriteRowRules
+{
+    /**
+     * @var ReadModifyWriteRule[]
+     */
+    private $rules = [];
+
+    /**
+     * Appends the value to the existing value of the cell. If targeted cell is unset,
+     * it will be treated as containing the empty string.
+     *
+     * @param string $familyName Family name of the row.
+     * @param string $qualifier Column qualifier of the row.
+     * @param string $value Value of the Column qualifier.
+     *
+     * @return ReadModifyWriteRowRules returns current ReadModifyWriteRowRules object.
+     */
+    public function append($familyName, $qualifier, $value)
+    {
+        $this->rules[] = (new ReadModifyWriteRule)
+            ->setFamilyName($familyName)
+            ->setColumnQualifier($qualifier)
+            ->setAppendValue($value);
+        return $this;
+    }
+
+    /**
+     * Adds `amount` to the existing value. If the targeted cell is unset, it will be treated
+     * as containing a zero. Otherwise, the targeted cell must containt an 8-byte value (interpreted
+     * as a 64-bit big-endian signed integer), or the entire request will fail.
+     *
+     * @param string $familyName Family name of the row.
+     * @param string $qualifier Column qualifier of the row.
+     * @param int $amount Amount to add to value of Column qualifier.
+     *
+     * @return ReadModifyWriteRowRules returns current ReadModifyWriteRowRules object.
+     */
+    public function increment($familyName, $qualifier, $amount)
+    {
+        $this->rules[] = (new ReadModifyWriteRule)
+            ->setFamilyName($familyName)
+            ->setColumnQualifier($qualifier)
+            ->setIncrementAmount($amount);
+        return $this;
+    }
+
+    /**
+     * Returns proto representation of ReadModifyWriteRule.
+     *
+     * @internal
+     * @access private
+     * @return ReadModifyWriteRule[] Returns array of ReadModifyWriteRule rules.
+     */
+    public function toProto()
+    {
+        return $this->rules;
+    }
+}