lib/decompress_unlz4.c

Source file repositories/reference/linux-study-clean/lib/decompress_unlz4.c

File Facts

System
Linux kernel
Corpus path
lib/decompress_unlz4.c
Extension
.c
Size
4279 bytes
Lines
218
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!outp) {
			error("Could not allocate output buffer");
			goto exit_0;
		}
	}

	if (input && fill) {
		error("Both input pointer and fill function provided,");
		goto exit_1;
	} else if (input) {
		inp = input;
	} else if (!fill) {
		error("NULL input pointer and missing fill function");
		goto exit_1;
	} else {
		inp = large_malloc(LZ4_compressBound(uncomp_chunksize));
		if (!inp) {
			error("Could not allocate input buffer");
			goto exit_1;
		}
	}
	inp_start = inp;

	if (posp)
		*posp = 0;

	if (fill) {
		size = fill(inp, 4);
		if (size < 4) {
			error("data corrupted");
			goto exit_2;
		}
	}

	chunksize = get_unaligned_le32(inp);
	if (chunksize == ARCHIVE_MAGICNUMBER) {
		if (!fill) {
			inp += 4;
			size -= 4;
		}
	} else {
		error("invalid header");
		goto exit_2;
	}

	if (posp)
		*posp += 4;

	for (;;) {

		if (fill) {
			size = fill(inp, 4);
			if (size == 0)
				break;
			if (size < 4) {
				error("data corrupted");
				goto exit_2;
			}
		} else if (size < 4) {
			/* empty or end-of-file */
			goto exit_3;
		}

		chunksize = get_unaligned_le32(inp);
		if (chunksize == ARCHIVE_MAGICNUMBER) {
			if (!fill) {
				inp += 4;
				size -= 4;
			}
			if (posp)
				*posp += 4;
			continue;
		}

		if (!fill && chunksize == 0) {
			/* empty or end-of-file */
			goto exit_3;
		}

		if (posp)
			*posp += 4;

		if (!fill) {
			inp += 4;
			size -= 4;
		} else {
			if (chunksize > LZ4_compressBound(uncomp_chunksize)) {
				error("chunk length is longer than allocated");
				goto exit_2;
			}

Annotation

Implementation Notes