/// This code is in the public domain.

module zlibx;

import std.zlib, etc.c.zlib, std.conv;
static import etc.c.zlib;
alias std.zlib.Z_SYNC_FLUSH Z_SYNC_FLUSH;

/// Avoid bug(?) in D zlib implementation with 7zip-generated zlib streams
ubyte[] exactUncompress(ubyte[] srcbuf, size_t destlen)
{
	etc.c.zlib.z_stream zs;

	auto destbuf = new ubyte[destlen];
	uint err;

	zs.next_in = srcbuf.ptr;
	zs.avail_in = to!uint(srcbuf.length);

	zs.next_out = destbuf.ptr;
	zs.avail_out = to!uint(destbuf.length);

	err = etc.c.zlib.inflateInit2(&zs, 15);
	if (err)
	{
		delete destbuf;
		throw new ZlibException(err);
	}

	err = etc.c.zlib.inflate(&zs, Z_SYNC_FLUSH);
	if (err != Z_OK && err != Z_STREAM_END)
	{
	Lerr:
		delete destbuf;
		etc.c.zlib.inflateEnd(&zs);
		throw new ZlibException(err);
	}
	if (zs.avail_out != 0)
		throw new Exception("Too little data in stream");

	err = etc.c.zlib.inflateEnd(&zs);
	if (err != Z_OK)
		goto Lerr;

	return destbuf;
}