herolib/aiprompts/v_advanced/compress.md

The compress module in V provides low-level functionalities for compressing and decompressing byte arrays.

Functions Overview (Low-Level):

• compress(data []u8, flags int) ![]u8: Compresses an array of bytes.
• decompress(data []u8, flags int) ![]u8: Decompresses an array of bytes.
• decompress_with_callback(data []u8, cb ChunkCallback, userdata voidptr, flags int) !u64: Decompresses byte arrays using a callback function for chunks.

Type Definition (Low-Level):

• ChunkCallback: A function type fn (chunk []u8, userdata voidptr) int used to receive decompressed chunks.

---

compress.gzip Module (High-Level Gzip Operations):

For high-level gzip compression and decompression, use the compress.gzip module. This module provides a more convenient and recommended way to handle gzip operations compared to the low-level compress module.

Key Features of compress.gzip:

• compress(data []u8, params CompressParams) ![]u8: Compresses data using gzip, allowing specification of CompressParams like compression_level (0-4095).
• decompress(data []u8, params DecompressParams) ![]u8: Decompresses gzip-compressed data, allowing specification of DecompressParams for verification.
• decompress_with_callback(data []u8, cb compr.ChunkCallback, userdata voidptr, params DecompressParams) !int: Decompresses gzip data with a callback for chunks, similar to the low-level version but for gzip streams.
• validate(data []u8, params DecompressParams) !GzipHeader: Validates a gzip header and returns its details.

Parameter Structures:

• CompressParams: Configures compression, primarily compression_level (0-4095).
• DecompressParams: Configures decompression, including verify_header_checksum, verify_length, and verify_checksum.
• GzipHeader: Represents the structure of a gzip header.

Inline Code Example (Gzip Compression/Decompression):

import compress.gzip

data := 'Hello, Gzip!'
compressed := gzip.compress(data.bytes(), compression_level: 4095)!
decompressed := gzip.decompress(compressed)!

// Check if decompressed data matches original
// if data.bytes() == decompressed { ... }

Important Note: Always prefer compress.gzip for general gzip compression/decompression tasks over the low-level compress module.