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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /include/linux/zutil.h
Initial import
Diffstat (limited to 'include/linux/zutil.h')
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diff --git a/include/linux/zutil.h b/include/linux/zutil.h
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+/* zutil.h -- internal interface and configuration of the compression library
+ * Copyright (C) 1995-1998 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+ part of the implementation of the compression library and is
+ subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id: zutil.h,v 1.1 2000/01/01 03:32:23 davem Exp $ */
+
+#ifndef _Z_UTIL_H
+#define _Z_UTIL_H
+
+#include <linux/zlib.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+typedef unsigned char uch;
+typedef unsigned short ush;
+typedef unsigned long ulg;
+
+ /* common constants */
+
+#define STORED_BLOCK 0
+#define STATIC_TREES 1
+#define DYN_TREES 2
+/* The three kinds of block type */
+
+#define MIN_MATCH 3
+#define MAX_MATCH 258
+/* The minimum and maximum match lengths */
+
+#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
+
+ /* target dependencies */
+
+ /* Common defaults */
+
+#ifndef OS_CODE
+# define OS_CODE 0x03 /* assume Unix */
+#endif
+
+ /* functions */
+
+typedef uLong (*check_func) (uLong check, const Byte *buf,
+ uInt len);
+
+
+ /* checksum functions */
+
+#define BASE 65521L /* largest prime smaller than 65536 */
+#define NMAX 5552
+/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+
+#define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
+#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
+#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
+#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
+#define DO16(buf) DO8(buf,0); DO8(buf,8);
+
+/* ========================================================================= */
+/*
+ Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+ return the updated checksum. If buf is NULL, this function returns
+ the required initial value for the checksum.
+ An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
+ much faster. Usage example:
+
+ uLong adler = adler32(0L, NULL, 0);
+
+ while (read_buffer(buffer, length) != EOF) {
+ adler = adler32(adler, buffer, length);
+ }
+ if (adler != original_adler) error();
+*/
+static inline uLong zlib_adler32(uLong adler,
+ const Byte *buf,
+ uInt len)
+{
+ unsigned long s1 = adler & 0xffff;
+ unsigned long s2 = (adler >> 16) & 0xffff;
+ int k;
+
+ if (buf == NULL) return 1L;
+
+ while (len > 0) {
+ k = len < NMAX ? len : NMAX;
+ len -= k;
+ while (k >= 16) {
+ DO16(buf);
+ buf += 16;
+ k -= 16;
+ }
+ if (k != 0) do {
+ s1 += *buf++;
+ s2 += s1;
+ } while (--k);
+ s1 %= BASE;
+ s2 %= BASE;
+ }
+ return (s2 << 16) | s1;
+}
+
+#endif /* _Z_UTIL_H */