something is working

2022-09-15 01:55:36 -04:00
parent a0aa251c27
commit f38e69883c
1123 changed files with 251731 additions and 11 deletions
@@ -0,0 +1,130 @@
+import * as zlib from 'zlib';
+
+import { LEGACY_HELLO_COMMAND } from '../../constants';
+import { PKG_VERSION, Snappy, ZStandard } from '../../deps';
+import { MongoDecompressionError, MongoInvalidArgumentError } from '../../error';
+import type { Callback } from '../../utils';
+import type { OperationDescription } from '../message_stream';
+
+/** @public */
+export const Compressor = Object.freeze({
+  none: 0,
+  snappy: 1,
+  zlib: 2,
+  zstd: 3
+} as const);
+
+/** @public */
+export type Compressor = typeof Compressor[CompressorName];
+
+/** @public */
+export type CompressorName = keyof typeof Compressor;
+
+export const uncompressibleCommands = new Set([
+  LEGACY_HELLO_COMMAND,
+  'saslStart',
+  'saslContinue',
+  'getnonce',
+  'authenticate',
+  'createUser',
+  'updateUser',
+  'copydbSaslStart',
+  'copydbgetnonce',
+  'copydb'
+]);
+
+const MAX_COMPRESSOR_ID = 3;
+const ZSTD_COMPRESSION_LEVEL = 3;
+
+// Facilitate compressing a message using an agreed compressor
+export function compress(
+  self: { options: OperationDescription & zlib.ZlibOptions },
+  dataToBeCompressed: Buffer,
+  callback: Callback<Buffer>
+): void {
+  const zlibOptions = {} as zlib.ZlibOptions;
+  switch (self.options.agreedCompressor) {
+    case 'snappy': {
+      if ('kModuleError' in Snappy) {
+        return callback(Snappy['kModuleError']);
+      }
+
+      if (Snappy[PKG_VERSION].major <= 6) {
+        Snappy.compress(dataToBeCompressed, callback);
+      } else {
+        Snappy.compress(dataToBeCompressed).then(
+          buffer => callback(undefined, buffer),
+          error => callback(error)
+        );
+      }
+      break;
+    }
+    case 'zlib':
+      // Determine zlibCompressionLevel
+      if (self.options.zlibCompressionLevel) {
+        zlibOptions.level = self.options.zlibCompressionLevel;
+      }
+      zlib.deflate(dataToBeCompressed, zlibOptions, callback as zlib.CompressCallback);
+      break;
+    case 'zstd':
+      if ('kModuleError' in ZStandard) {
+        return callback(ZStandard['kModuleError']);
+      }
+      ZStandard.compress(dataToBeCompressed, ZSTD_COMPRESSION_LEVEL).then(
+        buffer => callback(undefined, buffer),
+        error => callback(error)
+      );
+      break;
+    default:
+      throw new MongoInvalidArgumentError(
+        `Unknown compressor ${self.options.agreedCompressor} failed to compress`
+      );
+  }
+}
+
+// Decompress a message using the given compressor
+export function decompress(
+  compressorID: Compressor,
+  compressedData: Buffer,
+  callback: Callback<Buffer>
+): void {
+  if (compressorID < 0 || compressorID > MAX_COMPRESSOR_ID) {
+    throw new MongoDecompressionError(
+      `Server sent message compressed using an unsupported compressor. (Received compressor ID ${compressorID})`
+    );
+  }
+
+  switch (compressorID) {
+    case Compressor.snappy: {
+      if ('kModuleError' in Snappy) {
+        return callback(Snappy['kModuleError']);
+      }
+
+      if (Snappy[PKG_VERSION].major <= 6) {
+        Snappy.uncompress(compressedData, { asBuffer: true }, callback);
+      } else {
+        Snappy.uncompress(compressedData, { asBuffer: true }).then(
+          buffer => callback(undefined, buffer),
+          error => callback(error)
+        );
+      }
+      break;
+    }
+    case Compressor.zstd: {
+      if ('kModuleError' in ZStandard) {
+        return callback(ZStandard['kModuleError']);
+      }
+
+      ZStandard.decompress(compressedData).then(
+        buffer => callback(undefined, buffer),
+        error => callback(error)
+      );
+      break;
+    }
+    case Compressor.zlib:
+      zlib.inflate(compressedData, callback as zlib.CompressCallback);
+      break;
+    default:
+      callback(undefined, compressedData);
+  }
+}