compress_7z.c

/*
 * CDDL HEADER START
 *
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 *
 * CDDL HEADER END
*/
/*
 * Copyright 2023 Saso Kiselkov. All rights reserved.
 */
 
#include <string.h>
#include <stdlib.h>
 
#include <7z.h>
#include <7zAlloc.h>
#include <7zBuf.h>
#include <7zCrc.h>
#include <7zFile.h>
#include <7zVersion.h>
 
#include "acfutils/assert.h"
#include "acfutils/compress.h"
#include "acfutils/safe_alloc.h"
 
bool_t
test_7z(const void *in_buf, size_t len)
{
    static const uint8_t magic[] = { '7', 'z', 0xBC, 0xAF, 0x27, 0x1C };
    return (len >= sizeof (magic) &&
        memcmp(in_buf, magic, sizeof (magic)) == 0);
}
 
void *
decompress_7z(const char *filename, size_t *out_len)
{
#define kInputBufSize   ((size_t)1 << 18)
    void *out_buf = NULL;
    static const ISzAlloc g_Alloc = { SzAlloc, SzFree };
    ISzAlloc allocImp = g_Alloc;
    ISzAlloc allocTempImp = g_Alloc;
    CFileInStream archiveStream;
    CLookToRead2 lookStream;
    CSzArEx db;
    SRes res;
    UInt32 blockIndex = 0xFFFFFFFF;
    Byte *outBuffer = NULL;
    size_t outBufferSize = 0;
    size_t offset = 0;
    size_t outSizeProcessed = 0;
 
    if (InFile_Open(&archiveStream.file, filename))
        return (NULL);
 
    FileInStream_CreateVTable(&archiveStream);
    LookToRead2_CreateVTable(&lookStream, False);
    lookStream.buf = ISzAlloc_Alloc(&allocImp, kInputBufSize);
    lookStream.bufSize = kInputBufSize;
    lookStream.realStream = &archiveStream.vt;
    LookToRead2_INIT(&lookStream);
 
    CrcGenerateTable();
    SzArEx_Init(&db);
    res = SzArEx_Open(&db, &lookStream.vt, &allocImp, &allocTempImp);
    if (res != SZ_OK)
        goto out;
 
    res = SzArEx_Extract(&db, &lookStream.vt, 0, &blockIndex, &outBuffer,
        &outBufferSize, &offset, &outSizeProcessed, &allocImp,
        &allocTempImp);
    if (res != SZ_OK)
        goto out;
 
    *out_len = outBufferSize;
    out_buf = safe_malloc(outBufferSize);
    memcpy(out_buf, outBuffer, outBufferSize);
 
out:
    ISzAlloc_Free(&allocImp, outBuffer);
    SzArEx_Free(&db, &allocImp);
    ISzAlloc_Free(&allocImp, lookStream.buf);
 
    File_Close(&archiveStream.file);
 
    return (out_buf);
}