compress.szip #

Description

szip reads and writes ZIP archives in V, using stored or DEFLATE-compressed entries. ZIP64, multi-disk and encrypted archives are unsupported and return an error. Reading validates entry bounds, uncompressed sizes and CRC-32 checksums. New entry names are written as UTF-8 with the ZIP language encoding flag. Appending preserves the encoding flag and raw name bytes of existing entries.

Opening an entry by name in read-only mode returns an error when that entry is missing. extract_zip_to_dir rejects paths outside the destination and paths containing symbolic links. Extraction and the zip_files and zip_folder helpers propagate filesystem errors. The entry API retains its non-failing close() signature; use the helpers when write errors must be reported.

fn extract_zip_to_dir(file string, dir string) !bool

extract_zip_to_dir extracts entries beneath dir and reports invalid paths or I/O failures.

fn open(name string, level CompressionLevel, mode OpenMode) !&Zip

fn open_lazy(name string) !&Zip

open_lazy opens a readable archive without decompressing and caching the payload of every entry. Listing entries (total/name/size/is_dir) only needs the central directory, so scanning large archives stays fast; an entry is decoded (and validated) on demand when it is actually read.

fn zip_files(path_to_file []string, path_to_export_zip string) !

zip_files writes the supplied files to a ZIP archive and reports write failures.

fn zip_folder(folder string, zip_file string, opt ZipFolderOptions) !

zip_folder archives a directory, optionally omitting empty folders.

fn CompressionLevel.from[W](input W) !CompressionLevel

from returns the CompressionLevel value of an integer or of a field name, or an error if there is none.

fn OpenMode.from[W](input W) !OpenMode

from returns the OpenMode value of an integer or of a field name, or an error if there is none.

enum CompressionLevel {
	no_compression
	best_speed
	best_compression
	uber_compression
	default_level
	default_compression
}

enum OpenMode {
	write
	read_only
	append
}

struct Zip {
pub mut:
	path    string
	mode    OpenMode
	level   CompressionLevel
	entries []ZipEntry
	// write state
	current int = -1
	// cached file bytes for read
	filedata []u8
mut:
	directory_offset int
	validated        bool
}

fn (mut z Zip) close()

close flushes pending entries; use zip_files or zip_folder when write errors must be returned.

fn (mut z Zip) total() !int

fn (mut z Zip) open_entry_by_index(index int) !

fn (mut z Zip) open_entry(name string) !

open_entry finds a name case-insensitively when reading, or appends a new writable entry.

fn (mut z Zip) close_entry()

fn (mut z Zip) name() string

fn (mut z Zip) is_dir() !bool

fn (mut z Zip) size() u64

fn (mut z Zip) crc32() u32

fn (mut z Zip) index() !int

fn (mut z Zip) read_entry_buf(buf voidptr, in_bsize int) !int

fn (mut z Zip) read_entry_bytes() ![]u8

read_entry_bytes returns the fully validated, decompressed bytes of the current entry. Unlike read_entry_buf, the caller does not have to preallocate from the untrusted central-directory size: the entry is checked against its local header, decompressed and checksum-verified first, and the returned buffer is sized from the actual decoded length. The caller owns the returned array and must free it.

fn (mut z Zip) read_entry() !voidptr

read_entry allocates the current entry's bytes; the caller must free the returned buffer.

fn (mut z Zip) create_entry(name string) !

create_entry writes the file at name to the current archive entry.

fn (mut z Zip) extract_entry(path string) !

extract_entry writes the current archive entry to path.

fn (mut z Zip) write_entry(data []u8) !

write_entry appends bytes to the currently open writable entry.

struct ZipEntry {
pub mut:
	name   string
	method u16 // 0 = stored, 8 = deflate
	flags  u16
	crc32  u32
	size   u64 // uncompressed
	csize  u64 // compressed
	offset u64 // local header offset
	is_dir bool
	data   []u8 // uncompressed data (for write) / cached (for read)
}

struct ZipFolderOptions {
pub:
	omit_empty_folders bool
}