1/*
2 * Copyright (c) 2016-2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#pragma once
30#include <stdint.h>
31#include <stddef.h>
32#include <kern/assert.h>
33#include <machine/machlimits.h>
34#include "lz4_assembly_select.h"
35#include "lz4_constants.h"
36
37#define memcpy __builtin_memcpy
38
39#pragma mark - Building blocks
40
41// Represents a position in the input stream
42typedef struct { uint32_t offset; uint32_t word; } lz4_hash_entry_t;
43static const size_t lz4_hash_table_size = LZ4_COMPRESS_HASH_ENTRIES*sizeof(lz4_hash_entry_t);
44
45// Worker function for lz4 encode. Underlies both the buffer and stream encode operations.
46// Performs lz4 encoding of up to 2gb of data, updates dst_ptr and src_ptr to point to the
47// first byte of output and input that couldn't be completely processed, respectively.
48//
49// If skip_final_literals is 0, the entire src buffer is encoded, by emitting a final sequence of literals
50// at the end of the compressed payload.
51//
52// If skip_final_literals is not 0, this final literal sequence is not emitted, and the src buffer is
53// partially encoded (the length of this literal sequence varies).
54extern void lz4_encode_2gb(uint8_t **dst_ptr, size_t dst_size,
55 const uint8_t **src_ptr, const uint8_t *src_begin, size_t src_size,
56 lz4_hash_entry_t hash_table[LZ4_COMPRESS_HASH_ENTRIES],int skip_final_literals);
57
58extern int lz4_decode(uint8_t **dst_ptr, uint8_t *dst_begin, uint8_t *dst_end,
59 const uint8_t **src_ptr, const uint8_t *src_end);
60
61#if LZ4_ENABLE_ASSEMBLY_DECODE
62extern int lz4_decode_asm(uint8_t **dst_ptr, uint8_t *dst_begin, uint8_t *dst_end,
63 const uint8_t **src_ptr, const uint8_t *src_end);
64#endif
65
66#pragma mark - Buffer interfaces
67
68static const size_t lz4_encode_scratch_size = lz4_hash_table_size;
69static const size_t lz4_decode_scratch_size = 0;
70
71#pragma mark - Buffer interfaces (LZ4 RAW)
72
73size_t lz4raw_encode_buffer(uint8_t * __restrict dst_buffer, size_t dst_size,
74 const uint8_t * __restrict src_buffer, size_t src_size,
75 lz4_hash_entry_t hash_table[LZ4_COMPRESS_HASH_ENTRIES]);
76
77size_t lz4raw_decode_buffer(uint8_t * __restrict dst_buffer, size_t dst_size,
78 const uint8_t * __restrict src_buffer, size_t src_size,
79 void * __restrict work __attribute__((unused)));
80
81typedef __attribute__((__ext_vector_type__(8))) uint8_t vector_uchar8;
82typedef __attribute__((__ext_vector_type__(16))) uint8_t vector_uchar16;
83typedef __attribute__((__ext_vector_type__(32))) uint8_t vector_uchar32;
84typedef __attribute__((__ext_vector_type__(64))) uint8_t vector_uchar64;
85typedef __attribute__((__ext_vector_type__(16),__aligned__(1))) uint8_t packed_uchar16;
86typedef __attribute__((__ext_vector_type__(32),__aligned__(1))) uint8_t packed_uchar32;
87typedef __attribute__((__ext_vector_type__(64),__aligned__(1))) uint8_t packed_uchar64;
88
89typedef __attribute__((__ext_vector_type__(4))) uint16_t vector_ushort4;
90typedef __attribute__((__ext_vector_type__(4),__aligned__(2))) uint16_t packed_ushort4;
91
92typedef __attribute__((__ext_vector_type__(2))) int32_t vector_int2;
93typedef __attribute__((__ext_vector_type__(4))) int32_t vector_int4;
94typedef __attribute__((__ext_vector_type__(8))) int32_t vector_int8;
95
96typedef __attribute__((__ext_vector_type__(4))) uint32_t vector_uint4;
97
98#define UTIL_FUNCTION static inline __attribute__((__always_inline__)) __attribute__((__overloadable__))
99
100// Load N bytes from unaligned location PTR
101UTIL_FUNCTION uint16_t load2(const void * ptr) { uint16_t data; memcpy(&data,ptr,sizeof data); return data; }
102UTIL_FUNCTION uint32_t load4(const void * ptr) { uint32_t data; memcpy(&data,ptr,sizeof data); return data; }
103UTIL_FUNCTION uint64_t load8(const void * ptr) { uint64_t data; memcpy(&data,ptr,sizeof data); return data; }
104UTIL_FUNCTION vector_uchar16 load16(const void * ptr) { return (const vector_uchar16)*(const packed_uchar16 *)ptr; }
105UTIL_FUNCTION vector_uchar32 load32(const void * ptr) { return (const vector_uchar32)*(const packed_uchar32 *)ptr; }
106UTIL_FUNCTION vector_uchar64 load64(const void * ptr) { return (const vector_uchar64)*(const packed_uchar64 *)ptr; }
107
108// Store N bytes to unaligned location PTR
109UTIL_FUNCTION void store2(void * ptr,uint16_t data) { memcpy(ptr,&data,sizeof data); }
110UTIL_FUNCTION void store4(void * ptr,uint32_t data) { memcpy(ptr,&data,sizeof data); }
111UTIL_FUNCTION void store8(void * ptr,uint64_t data) { memcpy(ptr,&data,sizeof data); }
112UTIL_FUNCTION void store16(void * ptr,vector_uchar16 data) { *(packed_uchar16 *)ptr = (packed_uchar16)data; }
113UTIL_FUNCTION void store32(void * ptr,vector_uchar32 data) { *(packed_uchar32 *)ptr = (packed_uchar32)data; }
114UTIL_FUNCTION void store64(void * ptr,vector_uchar64 data) { *(packed_uchar64 *)ptr = (packed_uchar64)data; }
115
116// Load+Store N bytes from unaligned locations SRC to DST. No overlap allowed.
117UTIL_FUNCTION void copy8(void * dst,const void * src) { store8(dst,load8(src)); }
118UTIL_FUNCTION void copy16(void * dst,const void * src) { *(packed_uchar16 *)dst = *(const packed_uchar16 *)src; }
119UTIL_FUNCTION void copy32(void * dst,const void * src) { *(packed_uchar32 *)dst = *(const packed_uchar32 *)src; }
120
121#undef memcpy
122