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node.js zlib.constants用法及代碼示例

zlib.constants屬性用於產生列出與Zlib相關的常量的對象。

用法:

zlib.constants

返回值：它返回所有與Zlib相關的常量。



以下示例說明了Node.js中zlib.constants屬性的使用：

範例1：

// Node.js program to demonstrate      
// zlib.constants property 
// Including zlib module 
const zlib = require("zlib"); 
  
// Creating a buffer 
const buffer = Buffer.from('eJzT0yMA', 'base64'); 
  
// Calling unzip method 
zlib.unzip( 
  buffer, 
  
  // Using a Zlib constant 
  { finishFlush:zlib.constants.Z_SYNC_FLUSH }, 
  
  (err, buffer) => { 
  
    if (!err) { 
  
      console.log(buffer.toString()); 
    }  
    else
     { 
      console.log(err); 
    } 
  }); 
  
 // Calling "constants" property of zlib 
 zlib.constants;

輸出：

[Object:null prototype] {
  Z_NO_FLUSH:0,
  Z_PARTIAL_FLUSH:1,
  Z_SYNC_FLUSH:2,
  Z_FULL_FLUSH:3,
  Z_FINISH:4,
  Z_BLOCK:5,
  Z_OK:0,
  Z_STREAM_END:1,
  Z_NEED_DICT:2,
  Z_ERRNO:-1,
  Z_STREAM_ERROR:-2,
  Z_DATA_ERROR:-3,
  Z_MEM_ERROR:-4,
  Z_BUF_ERROR:-5,
  Z_VERSION_ERROR:-6,
  Z_NO_COMPRESSION:0,
  Z_BEST_SPEED:1,
  Z_BEST_COMPRESSION:9,
  Z_DEFAULT_COMPRESSION:-1,
  Z_FILTERED:1,
  Z_HUFFMAN_ONLY:2,
  Z_RLE:3,
  Z_FIXED:4,
  Z_DEFAULT_STRATEGY:0,
  ZLIB_VERNUM:4784,
  DEFLATE:1,
  INFLATE:2,
  GZIP:3,
  GUNZIP:4,
  DEFLATERAW:5,
  INFLATERAW:6,
  UNZIP:7,
  BROTLI_DECODE:8,
  BROTLI_ENCODE:9,
  Z_MIN_WINDOWBITS:8,
  Z_MAX_WINDOWBITS:15,
  Z_DEFAULT_WINDOWBITS:15,
  Z_MIN_CHUNK:64,
  Z_MAX_CHUNK:Infinity,
  Z_DEFAULT_CHUNK:16384,
  Z_MIN_MEMLEVEL:1,
  Z_MAX_MEMLEVEL:9,
  Z_DEFAULT_MEMLEVEL:8,
  Z_MIN_LEVEL:-1,
  Z_MAX_LEVEL:9,
  Z_DEFAULT_LEVEL:-1,
  BROTLI_OPERATION_PROCESS:0,
  BROTLI_OPERATION_FLUSH:1,
  BROTLI_OPERATION_FINISH:2,
  BROTLI_OPERATION_EMIT_METADATA:3,
  BROTLI_PARAM_MODE:0,
  BROTLI_MODE_GENERIC:0,
  BROTLI_MODE_TEXT:1,
  BROTLI_MODE_FONT:2,
  BROTLI_DEFAULT_MODE:0,
  BROTLI_PARAM_QUALITY:1,
  BROTLI_MIN_QUALITY:0,
  BROTLI_MAX_QUALITY:11,
  BROTLI_DEFAULT_QUALITY:11,
  BROTLI_PARAM_LGWIN:2,
  BROTLI_MIN_WINDOW_BITS:10,
  BROTLI_MAX_WINDOW_BITS:24,
  BROTLI_LARGE_MAX_WINDOW_BITS:30,
  BROTLI_DEFAULT_WINDOW:22,
  BROTLI_PARAM_LGBLOCK:3,
  BROTLI_MIN_INPUT_BLOCK_BITS:16,
  BROTLI_MAX_INPUT_BLOCK_BITS:24,
  BROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING:4,
  BROTLI_PARAM_SIZE_HINT:5,
  BROTLI_PARAM_LARGE_WINDOW:6,
  BROTLI_PARAM_NPOSTFIX:7,
  BROTLI_PARAM_NDIRECT:8,
  BROTLI_DECODER_RESULT_ERROR:0,
  BROTLI_DECODER_RESULT_SUCCESS:1,
  BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT:2,
  BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT:3,
  BROTLI_DECODER_PARAM_DISABLE_RING_BUFFER_REALLOCATION:0,
  BROTLI_DECODER_PARAM_LARGE_WINDOW:1,
  BROTLI_DECODER_NO_ERROR:0,
  BROTLI_DECODER_SUCCESS:1,
  BROTLI_DECODER_NEEDS_MORE_INPUT:2,
  BROTLI_DECODER_NEEDS_MORE_OUTPUT:3,
  BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE:-1,
  BROTLI_DECODER_ERROR_FORMAT_RESERVED:-2,
  BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE:-3,
  BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET:-4,
  BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME:-5,
  BROTLI_DECODER_ERROR_FORMAT_CL_SPACE:-6,
  BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE:-7,
  BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT:-8,
  BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1:-9,
  BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2:-10,
  BROTLI_DECODER_ERROR_FORMAT_TRANSFORM:-11,
  BROTLI_DECODER_ERROR_FORMAT_DICTIONARY:-12,
  BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS:-13,
  BROTLI_DECODER_ERROR_FORMAT_PADDING_1:-14,
  BROTLI_DECODER_ERROR_FORMAT_PADDING_2:-15,
  BROTLI_DECODER_ERROR_FORMAT_DISTANCE:-16,
  BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET:-19,
  BROTLI_DECODER_ERROR_INVALID_ARGUMENTS:-20,
  BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES:-21,
  BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS:-22,
  BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP:-25,
  BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1:-26,
  BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2:-27,
  BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES:-30,
  BROTLI_DECODER_ERROR_UNREACHABLE:-31 }
..

範例2：

// Node.js program to demonstrate      
// zlib.constants property 
// Including zlib module 
const zlib = require("zlib"); 
  
// Creating a buffer 
const buffer = Buffer.from('eJzT0yMA', 'base64'); 
  
// Calling unzip method 
zlib.unzip( 
  buffer, 
  
  // Using a different Zlib constant 
  { finishFlush:zlib.constants.Z_NO_FLUSH }, 
  
  (err, buffer) => { 
  
    if (!err) { 
  
      console.log(buffer.toString()); 
    }  
    else
     { 
      console.log(err); 
    } 
  }); 
  
 // Calling "constants" property of zlib 
 zlib.constants;

輸出

[Object:null prototype] {
  Z_NO_FLUSH:0,
  Z_PARTIAL_FLUSH:1,
  Z_SYNC_FLUSH:2,
  Z_FULL_FLUSH:3,
  Z_FINISH:4,
  Z_BLOCK:5,
  Z_OK:0,
  Z_STREAM_END:1,
  Z_NEED_DICT:2,
  Z_ERRNO:-1,
  Z_STREAM_ERROR:-2,
  Z_DATA_ERROR:-3,
  Z_MEM_ERROR:-4,
  Z_BUF_ERROR:-5,
  Z_VERSION_ERROR:-6,
  Z_NO_COMPRESSION:0,
  Z_BEST_SPEED:1,
  Z_BEST_COMPRESSION:9,
  Z_DEFAULT_COMPRESSION:-1,
  Z_FILTERED:1,
  Z_HUFFMAN_ONLY:2,
  Z_RLE:3,
  Z_FIXED:4,
  Z_DEFAULT_STRATEGY:0,
  ZLIB_VERNUM:4784,
  DEFLATE:1,
  INFLATE:2,
  GZIP:3,
  GUNZIP:4,
  DEFLATERAW:5,
  INFLATERAW:6,
  UNZIP:7,
  BROTLI_DECODE:8,
  BROTLI_ENCODE:9,
  Z_MIN_WINDOWBITS:8,
  Z_MAX_WINDOWBITS:15,
  Z_DEFAULT_WINDOWBITS:15,
  Z_MIN_CHUNK:64,
  Z_MAX_CHUNK:Infinity,
  Z_DEFAULT_CHUNK:16384,
  Z_MIN_MEMLEVEL:1,
  Z_MAX_MEMLEVEL:9,
  Z_DEFAULT_MEMLEVEL:8,
  Z_MIN_LEVEL:-1,
  Z_MAX_LEVEL:9,
  Z_DEFAULT_LEVEL:-1,
  BROTLI_OPERATION_PROCESS:0,
  BROTLI_OPERATION_FLUSH:1,
  BROTLI_OPERATION_FINISH:2,
  BROTLI_OPERATION_EMIT_METADATA:3,
  BROTLI_PARAM_MODE:0,
  BROTLI_MODE_GENERIC:0,
  BROTLI_MODE_TEXT:1,
  BROTLI_MODE_FONT:2,
  BROTLI_DEFAULT_MODE:0,
  BROTLI_PARAM_QUALITY:1,
  BROTLI_MIN_QUALITY:0,
  BROTLI_MAX_QUALITY:11,
  BROTLI_DEFAULT_QUALITY:11,
  BROTLI_PARAM_LGWIN:2,
  BROTLI_MIN_WINDOW_BITS:10,
  BROTLI_MAX_WINDOW_BITS:24,
  BROTLI_LARGE_MAX_WINDOW_BITS:30,
  BROTLI_DEFAULT_WINDOW:22,
  BROTLI_PARAM_LGBLOCK:3,
  BROTLI_MIN_INPUT_BLOCK_BITS:16,
  BROTLI_MAX_INPUT_BLOCK_BITS:24,
  BROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING:4,
  BROTLI_PARAM_SIZE_HINT:5,
  BROTLI_PARAM_LARGE_WINDOW:6,
  BROTLI_PARAM_NPOSTFIX:7,
  BROTLI_PARAM_NDIRECT:8,
  BROTLI_DECODER_RESULT_ERROR:0,
  BROTLI_DECODER_RESULT_SUCCESS:1,
  BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT:2,
  BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT:3,
  BROTLI_DECODER_PARAM_DISABLE_RING_BUFFER_REALLOCATION:0,
  BROTLI_DECODER_PARAM_LARGE_WINDOW:1,
  BROTLI_DECODER_NO_ERROR:0,
  BROTLI_DECODER_SUCCESS:1,
  BROTLI_DECODER_NEEDS_MORE_INPUT:2,
  BROTLI_DECODER_NEEDS_MORE_OUTPUT:3,
  BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE:-1,
  BROTLI_DECODER_ERROR_FORMAT_RESERVED:-2,
  BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE:-3,
  BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET:-4,
  BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME:-5,
  BROTLI_DECODER_ERROR_FORMAT_CL_SPACE:-6,
  BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE:-7,
  BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT:-8,
  BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1:-9,
  BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2:-10,
  BROTLI_DECODER_ERROR_FORMAT_TRANSFORM:-11,
  BROTLI_DECODER_ERROR_FORMAT_DICTIONARY:-12,
  BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS:-13,
  BROTLI_DECODER_ERROR_FORMAT_PADDING_1:-14,
  BROTLI_DECODER_ERROR_FORMAT_PADDING_2:-15,
  BROTLI_DECODER_ERROR_FORMAT_DISTANCE:-16,
  BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET:-19,
  BROTLI_DECODER_ERROR_INVALID_ARGUMENTS:-20,
  BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES:-21,
  BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS:-22,
  BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP:-25,
  BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1:-26,
  BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2:-27,
  BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES:-30,
  BROTLI_DECODER_ERROR_UNREACHABLE:-31 }
..

參考： https://nodejs.org/api/zlib.html#zlib_zlib_constants_1




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注：本文由純淨天空篩選整理自nidhi1352singh大神的英文原創作品 Node.js | zlib.constants Property。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。