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    Import std.compress.deflate

    std.compress.deflate

    Deflate, Zlib, and Gzip compression.

    Deflate (RFC 1951), Zlib (RFC 1950), and Gzip (RFC 1952), over zlib-ng. Each one's Compress and Decompress work at once, and its Compressor and Decompressor take bytes in turn and give what came out of them so far, for data that comes in parts. Levels go from 0, stored as it is, to 9, the smallest, and are 6 by default. A Gzip Decompress reads members one after another, as gunzip does, and a Gzip Compress writes one member, with no name, time, or OS in its header.

    Examples

    // Each format's Compressor and Decompressor take bytes in turn.
Local compressor = ZlibCompressor(9)
Local packed = compressor.Add("a part, and ".Bytes)
packed.AddAll(compressor.Add("the rest".Bytes))
packed.AddAll(compressor.Finish())
Local decompressor = ZlibDecompressor()
Local text = Try decompressor.Add(packed)
text.AddAll(Try decompressor.Finish())
Expect(String.FromUtf8(text) == "a part, and the rest")
Local raw = DeflateCompressor()
Local deflated = raw.Add("raw".Bytes)
deflated.AddAll(raw.Finish())
Local inflate = DeflateDecompressor()
Local back = Try inflate.Add(deflated)
back.AddAll(Try inflate.Finish())
Expect(back == "raw".Bytes)

    std/compress/deflate.fb

    Types

    Deflate struct 

    Public Struct Deflate

    Deflate's raw bytes, which zip entries and PNG's data are in.

    Examples

    Local data = "hello, hello, hello, hello".Repeated(100).Bytes
Local packed = Deflate.Compress(data)
Expect(packed.Count < data.Count)
Local unpacked = Try Deflate.Decompress(packed)
Expect(unpacked == data)

    std/compress/deflate.fb, line 64

    • @PanicsAtCaller Public Static Method Compress(data: UInt8[], level: Int = 6): UInt8[] static method #

      The data, compressed at the level. Panics when the level isn't from 0 to 9.

    • @PanicsAtCaller Public Static Method Decompress(data: UInt8[], limit: Int = MOST_BYTES): UInt8[] Throws IOError static method #

      The bytes the data is compressed from, or an IOError when it isn't Deflate's, ends early, or would come to more than limit bytes. Panics when the limit is negative.

    Zlib struct 

    Public Struct Zlib

    Zlib's bytes: Deflate's, with a header and an Adler-32 checksum.

    Examples

    Local data = "hello, hello, hello, hello".Repeated(100).Bytes
Local packed = Zlib.Compress(data)
Expect(packed.Count < data.Count)
Local unpacked = Try Zlib.Decompress(packed)
Expect(unpacked == data)

    std/compress/deflate.fb, line 96

    • @PanicsAtCaller Public Static Method Compress(data: UInt8[], level: Int = 6): UInt8[] static method #

      The data, compressed at the level. Panics when the level isn't from 0 to 9.

    • @PanicsAtCaller Public Static Method Decompress(data: UInt8[], limit: Int = MOST_BYTES): UInt8[] Throws IOError static method #

      The bytes the data is compressed from, or an IOError when it isn't Zlib's, ends early, or would come to more than limit bytes. Panics when the limit is negative.

    Gzip struct 

    Public Struct Gzip

    Gzip's bytes, of .gz files and HTTP's gzip: Deflate's, with a header and a CRC-32 checksum.

    Examples

    Local data = "the same words, the same words, the same words".Bytes
Local gz = Gzip.Compress(data, 9)
Expect(gz[0] == 0x1F && gz[1] == 0x8B)
Local unpacked = Try Gzip.Decompress(gz)
Expect(unpacked == data)

    std/compress/deflate.fb, line 127

    • @PanicsAtCaller Public Static Method Compress(data: UInt8[], level: Int = 6): UInt8[] static method #

      The data, compressed at the level, as one member. Panics when the level isn't from 0 to 9.

    • @PanicsAtCaller Public Static Method Decompress(data: UInt8[], limit: Int = MOST_BYTES): UInt8[] Throws IOError static method #

      The bytes the data is compressed from, each member's after the last's, or an IOError when it isn't Gzip's, ends early, or would come to more than limit bytes. Panics when the limit is negative.

    DeflateCompressor class 

    Public Class DeflateCompressor Implements Coder

    Deflate's bytes made in turn: Add gives what compressing the bytes it takes has made so far, and Finish what's left, which ends them, and starts again.

    std/compress/deflate.fb, line 151

    • @PanicsAtCaller Public New(level: Int = 6) constructor #

      A new DeflateCompressor at the level. Panics when it isn't from 0 to 9.

    • Public Method Add(data: UInt8[]): UInt8[] method #

      Compresses data, and gives the Deflate bytes it has made so far, which can be none, as it holds some back to compress with what comes next.

    • Public Method Finish(): UInt8[] method #

      The rest of the bytes, which end the stream, and starts again, for another.

    ZlibCompressor class 

    Public Class ZlibCompressor Implements Coder

    Zlib's bytes made in turn, as DeflateCompressor makes Deflate's.

    std/compress/deflate.fb, line 172

    • @PanicsAtCaller Public New(level: Int = 6) constructor #

      A new ZlibCompressor at the level. Panics when it isn't from 0 to 9.

    • Public Method Add(data: UInt8[]): UInt8[] method #

      Compresses data, and gives the Zlib bytes it has made so far, which can be none, as it holds some back to compress with what comes next.

    • Public Method Finish(): UInt8[] method #

      The rest of the bytes, which end the stream, and starts again, for another.

    GzipCompressor class 

    Public Class GzipCompressor Implements Coder

    Gzip's bytes made in turn, as DeflateCompressor makes Deflate's, each Finish ending a member.

    Examples

    Local compressor = GzipCompressor()
Local gz = compressor.Add("first part, ".Bytes)
gz.AddAll(compressor.Add("second part".Bytes))
gz.AddAll(compressor.Finish())
Expect(String.FromUtf8(Try Gzip.Decompress(gz)) == "first part, second part")

    std/compress/deflate.fb, line 205

    • @PanicsAtCaller Public New(level: Int = 6) constructor #

      A new GzipCompressor at the level. Panics when it isn't from 0 to 9.

    • Public Method Add(data: UInt8[]): UInt8[] method #

      Compresses data, and gives the Gzip bytes it has made so far, which can be none, as it holds some back to compress with what comes next.

    • Public Method Finish(): UInt8[] method #

      The rest of the bytes, which end the member, and starts again, for another.

    DeflateDecompressor class 

    Public Class DeflateDecompressor Implements Coder

    Deflate's bytes taken in turn: Add gives what the bytes it takes decompress to so far, and Finish what's left once they've all been added, and starts again. Each throws an IOError when the bytes aren't Deflate's or would come to more than the limit, and Finish when they end early. Bytes after the end are an IOError too.

    std/compress/deflate.fb, line 229

    • @PanicsAtCaller Public New(limit: Int = MOST_BYTES) constructor #

      A new DeflateDecompressor that gives at most limit bytes. Panics when the limit is negative.

    • Public Method Add(data: UInt8[]): UInt8[] Throws IOError method #

      Decompresses data, and gives the bytes it comes to so far. Throws an IOError when the bytes aren't Deflate's, or would come to more than the limit.

    • Public Method Finish(): UInt8[] Throws IOError method #

      The rest of the bytes, once every one is added, and starts again. Throws an IOError when the stream ended early.

    ZlibDecompressor class 

    Public Class ZlibDecompressor Implements Coder

    Zlib's bytes taken in turn, as DeflateDecompressor takes Deflate's.

    std/compress/deflate.fb, line 260

    • @PanicsAtCaller Public New(limit: Int = MOST_BYTES) constructor #

      A new ZlibDecompressor that gives at most limit bytes. Panics when the limit is negative.

    • Public Method Add(data: UInt8[]): UInt8[] Throws IOError method #

      Decompresses data, and gives the bytes it comes to so far. Throws an IOError when the bytes aren't Zlib's, or would come to more than the limit.

    • Public Method Finish(): UInt8[] Throws IOError method #

      The rest of the bytes, once every one is added, and starts again. Throws an IOError when the stream ended early.

    GzipDecompressor class 

    Public Class GzipDecompressor Implements Coder

    Gzip's bytes taken in turn, as DeflateDecompressor takes Deflate's, a member after another.

    Examples

    Local gz = Gzip.Compress("in two halves".Bytes)
Local decompressor = GzipDecompressor()
Local half = gz.Count / 2
Local text = Try decompressor.Add(gz[0..half])
text.AddAll(Try decompressor.Add(gz[half..gz.Count]))
text.AddAll(Try decompressor.Finish())
Expect(String.FromUtf8(text) == "in two halves")

    std/compress/deflate.fb, line 305

    • @PanicsAtCaller Public New(limit: Int = MOST_BYTES) constructor #

      A new GzipDecompressor that gives at most limit bytes. Panics when the limit is negative.

    • Public Method Add(data: UInt8[]): UInt8[] Throws IOError method #

      Decompresses data, and gives the bytes it comes to so far. Throws an IOError when the bytes aren't Gzip's, or would come to more than the limit.

    • Public Method Finish(): UInt8[] Throws IOError method #

      The rest of the bytes, once every one is added, and starts again. Throws an IOError when the stream ended early.

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