Differential D25039 Diff 96 src/filesystem/memory/ArcanistHostMemorySnapshot.php

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src/filesystem/memory/ArcanistHostMemorySnapshot.php

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				<?php

				final class ArcanistHostMemorySnapshot
				extends Phobject {

				private $memorySnapshot;

				public static function newFromRawMeminfo($meminfo_source, $meminfo_raw) {
				$snapshot = new self();

				$snapshot->memorySnapshot = $snapshot->readMeminfoSnapshot(
				$meminfo_source,
				$meminfo_raw);

				return $snapshot;
				}

				public function getTotalSwapBytes() {
				$info = $this->getMemorySnapshot();
				return $info['swap.total'];
				}

				private function getMemorySnapshot() {
				if ($this->memorySnapshot === null) {
				$this->memorySnapshot = $this->newMemorySnapshot();
				}

				return $this->memorySnapshot;
				}

				private function newMemorySnapshot() {
				$meminfo_source = '/proc/meminfo';
				list($meminfo_raw) = execx('cat %s', $meminfo_source);
				return $this->readMeminfoSnapshot($meminfo_source, $meminfo_raw);
				}

				private function readMeminfoSnapshot($meminfo_source, $meminfo_raw) {
				$meminfo_pattern = '/^([^:]+):\s+(\S+)(?:\s+(kB))?\z/';

				$meminfo_map = array();

				$meminfo_lines = phutil_split_lines($meminfo_raw, false);
				foreach ($meminfo_lines as $meminfo_line) {
				$meminfo_parts = phutil_preg_match($meminfo_pattern, $meminfo_line);

				if (!$meminfo_parts) {
				throw new Exception(
				pht(
				'Unable to parse line in meminfo source "%s": "%s".',
				$meminfo_source,
				$meminfo_line));
				}

				$meminfo_key = $meminfo_parts[1];
				$meminfo_value = $meminfo_parts[2];
				$meminfo_unit = idx($meminfo_parts, 3);

				if (isset($meminfo_map[$meminfo_key])) {
				throw new Exception(
				pht(
				'Encountered duplicate meminfo key "%s" in meminfo source "%s".',
				$meminfo_key,
				$meminfo_source));
				}

				$meminfo_map[$meminfo_key] = array(
				'value' => $meminfo_value,
				'unit' => $meminfo_unit,
				);
				}

				$swap_total_bytes = $this->readMeminfoBytes(
				$meminfo_source,
				$meminfo_map,
				'SwapTotal');

				return array(
				'swap.total' => $swap_total_bytes,
				);
				}

				private function readMeminfoBytes(
				$meminfo_source,
				$meminfo_map,
				$meminfo_key) {

				$meminfo_integer = $this->readMeminfoIntegerValue(
				$meminfo_source,
				$meminfo_map,
				$meminfo_key);

				$meminfo_unit = $meminfo_map[$meminfo_key]['unit'];
				if ($meminfo_unit === null) {
				throw new Exception(
				pht(
				'Expected to find a byte unit for meminfo key "%s" in meminfo '.
				'source "%s", found no unit.',
				$meminfo_key,
				$meminfo_source));
				}

				if ($meminfo_unit !== 'kB') {
				throw new Exception(
				pht(
				'Expected unit for meminfo key "%s" in meminfo source "%s" '.
				'to be "kB", found "%s".',
				$meminfo_key,
				$meminfo_source,
				$meminfo_unit));
				}

				$meminfo_bytes = ($meminfo_integer * 1024);

				return $meminfo_bytes;
				}

				private function readMeminfoIntegerValue(
				$meminfo_source,
				$meminfo_map,
				$meminfo_key) {

				$meminfo_value = $this->readMeminfoValue(
				$meminfo_source,
				$meminfo_map,
				$meminfo_key);

				if (!phutil_preg_match('/^\d+\z/', $meminfo_value)) {
				throw new Exception(
				pht(
				'Expected to find an integer value for meminfo key "%s" in '.
				'meminfo source "%s", found "%s".',
				$meminfo_key,
				$meminfo_source,
				$meminfo_value));
				}

				return (int)$meminfo_value;
				}

				private function readMeminfoValue(
				$meminfo_source,
				$meminfo_map,
				$meminfo_key) {

				if (!isset($meminfo_map[$meminfo_key])) {
				throw new Exception(
				pht(
				'Expected to find meminfo key "%s" in meminfo source "%s".',
				$meminfo_key,
				$meminfo_source));
				}

				return $meminfo_map[$meminfo_key]['value'];
				}

				}