Node.js - buffermodule
Voorbeeld
Skakel die string "abc" om in 'n stroom binêre data:
var buf = Buffer.from('abc');
console.log(buf);
Definisie en gebruik
Die buffermodule bied 'n manier om strome van binêre data te hanteer.
Die Buffer-objek is 'n globale objek in Node.js, en dit is nie nodig om dit in te voer met die requiresleutelwoord nie.
Sintaksis
Die sintaksis vir die skep van 'n leë buffer van die lengte 15:
var buf = Buffer.alloc(15);
Buffer eienskappe en metodes
| Method | Description |
|---|---|
| alloc() | Creates a Buffer object of the specified length |
| allocUnsafe() | Creates a non-zero-filled Buffer of the specified length |
| allocUnsafeSlow | Creates a non-zero-filled and non-pooled Buffer of the specified length |
| byteLength() | Returns the numbers of bytes in a specified object |
| compare() | Compares two Buffer objects |
| concat() | Concatenates an array of Buffer objects into one Buffer object |
| copy() | Copies the specified number of bytes of a Buffer object |
| entries() | Returns an iterator of "index" "byte" pairs of a Buffer object |
| equals() | Compares two Buffer objects, and returns true if it is a match, otherwise false |
| fill() | Fills a Buffer object with the specified values |
| from() | Creates a Buffer object from an object (string/array/buffer) |
| includes() | Checks if the Buffer object contains the specified value. Returns true if there is a match, otherwise false |
| indexOf() | Checks if the Buffer object contains the specified value. Returns the first occurrence, otherwise -1 |
| isBuffer() | Checks if an object is a Buffer object |
| isEncoding() | Checks if the Buffer object supports the specified encoding |
| keys() | Returns an array of keys in a Buffer object |
| lastIndexOf() | Checks if the Buffer object contains the specified value. Returns the first occurrence, starting from the end, otherwise -1 |
| length | Returns the length of a Buffer object, in bytes |
| poolSize | Sets or returns the number of bytes used for pooling |
| readDoubleBE() | Reads a 64 bit double from a Buffer object, returns the result in big endian |
| readDoubleLE() | Reads a 64 bit double from a Buffer object, returns the result in little endian |
| readFloatBE() | Reads a 32 bit float from a Buffer object, returns the result in big endian |
| readFloatLE() | Reads a 32 bit float from a Buffer object, returns the result in little endian |
| readInt8() | Reads a 8 bit integer from a Buffer object |
| readInt16BE() | Reads a 16 bit integer from a Buffer object, returns the result in big endian |
| readInt16LE() | Reads a 16 bit integer from a Buffer object, returns the result in little endian |
| readInt32BE() | Reads a 32 bit integer from a Buffer object, returns the result in big endian |
| readInt32LE() | Reads a 32 bit integer from a Buffer object, returns the result in little endian |
| readIntBE() | Reads the specified number of bytes from a Buffer object, returns the result in big endian |
| readIntLE() | Reads the specified number of bytes from a Buffer object, returns the result in little endian |
| readUInt8() | Reads an unsigned 8 bit integer from a Buffer object |
| readUInt16BE() | Reads an unsigned 16 bit integer from a Buffer object, returns the result in big endian |
| readUInt16LE() | Reads an unsigned 16 bit integer from a Buffer object, returns the result in little endian |
| readUInt32BE() | Reads an unsigned 32 bit integer from a Buffer object, returns the result in big endian |
| readUInt32LE() | Reads an unsigned 32 bit integer from a Buffer object, returns the result in little endian |
| readUintBE() | Reads the specified number of bytes from a Buffer object, returns the result as an unsigned integer |
| readUIntLE() | Reads the specified number of bytes from a Buffer object, returns the result as an unsigned integer |
| slice() | Slices a Buffer object into a new Buffer objects starting and ending at the specified positions |
| swap16() | Swaps the byte-order of a 16 bit Buffer object |
| swap32() | Swaps the byte-order of a 32 bit Buffer object |
| swap64() | Swaps the byte-order of a 64 bit Buffer object |
| toString() | Returns a string version of a Buffer object |
| toJSON() | Returns a JSON version of a Buffer object |
| values() | Returns an array of values in a Buffer object |
| write() | Writes a specified string to a Buffer object |
| writeDoubleBE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 64 bit double. |
| writeDoubleLE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 64 bit double. |
| writeFloatBE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 32 bit float. |
| writeFloatLE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 32 bit float. |
| writeInt8() | Writes the specified bytes to a Buffer object. The bytes should be 8 bit integer |
| writeInt16BE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 16 bit integer. |
| writeInt16LE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 16 bit integer. |
| writeInt32BE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 32 bit integer. |
| writeInt32LE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 32 bit integer. |
| writeIntBE() | Writes the specified bytes, using big endian, to a Buffer object. |
| writeIntLE() | Writes the specified bytes, using little endian, to a Buffer object. |
| writeUInt8() | Writes the specified bytes to a Buffer object. The bytes should be 8 bit unsigned integer |
| writeUInt16BE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 16 bit unsigned integer. |
| writeUInt16LE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 16 bit unsigned integer. |
| writeUInt32BE() | Writes the specified bytes, using big endian, to a Buffer object. The bytes should be 32 bit unsigned integer. |
| writeUInt32LE() | Writes the specified bytes, using little endian, to a Buffer object. The bytes should be 32 bit unsigned integer. |
| writeUIntBE() | Writes the specified bytes, using big endian, to a Buffer object |
| writeUIntLE() | Writes the specified bytes, using little endian, to a Buffer object |