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/limits.h>
34 #include "lz4_assembly_select.h"
35 #include "lz4_constants.h"
36
37 #if CONFIG_IO_COMPRESSION_STATS
38 #include <string.h>
39 #else
40 #define memcpy __builtin_memcpy
41 #endif
42
43 #pragma mark - Building blocks
44
45 // Represents a position in the input stream
46 typedef struct { uint32_t offset; uint32_t word; } lz4_hash_entry_t;
47 static const size_t lz4_hash_table_size = LZ4_COMPRESS_HASH_ENTRIES * sizeof(lz4_hash_entry_t);
48
49 // Worker function for lz4 encode. Underlies both the buffer and stream encode operations.
50 // Performs lz4 encoding of up to 2gb of data, updates dst_ptr and src_ptr to point to the
51 // first byte of output and input that couldn't be completely processed, respectively.
52 //
53 // If skip_final_literals is 0, the entire src buffer is encoded, by emitting a final sequence of literals
54 // at the end of the compressed payload.
55 //
56 // If skip_final_literals is not 0, this final literal sequence is not emitted, and the src buffer is
57 // partially encoded (the length of this literal sequence varies).
58 extern void lz4_encode_2gb(uint8_t **dst_ptr, size_t dst_size,
59 const uint8_t **src_ptr, const uint8_t *src_begin, size_t src_size,
60 lz4_hash_entry_t hash_table[LZ4_COMPRESS_HASH_ENTRIES], int skip_final_literals);
61
62 extern int lz4_decode(uint8_t **dst_ptr, uint8_t *dst_begin, uint8_t *dst_end,
63 const uint8_t **src_ptr, const uint8_t *src_end);
64
65 #if LZ4_ENABLE_ASSEMBLY_DECODE
66 extern int lz4_decode_asm(uint8_t **dst_ptr, uint8_t *dst_begin, uint8_t *dst_end,
67 const uint8_t **src_ptr, const uint8_t *src_end);
68 #endif
69
70 #pragma mark - Buffer interfaces
71
72 static const size_t lz4_encode_scratch_size = lz4_hash_table_size;
73 static const size_t lz4_decode_scratch_size = 0;
74
75 #pragma mark - Buffer interfaces (LZ4 RAW)
76
77 size_t lz4raw_encode_buffer(uint8_t * __restrict dst_buffer, size_t dst_size,
78 const uint8_t * __restrict src_buffer, size_t src_size,
79 lz4_hash_entry_t hash_table[LZ4_COMPRESS_HASH_ENTRIES]);
80
81 size_t lz4raw_decode_buffer(uint8_t * __restrict dst_buffer, size_t dst_size,
82 const uint8_t * __restrict src_buffer, size_t src_size,
83 void * __restrict work __attribute__((unused)));
84
85 typedef __attribute__((__ext_vector_type__(8))) uint8_t vector_uchar8;
86 typedef __attribute__((__ext_vector_type__(16))) uint8_t vector_uchar16;
87 typedef __attribute__((__ext_vector_type__(32))) uint8_t vector_uchar32;
88 typedef __attribute__((__ext_vector_type__(64))) uint8_t vector_uchar64;
89 typedef __attribute__((__ext_vector_type__(16), __aligned__(1))) uint8_t packed_uchar16;
90 typedef __attribute__((__ext_vector_type__(32), __aligned__(1))) uint8_t packed_uchar32;
91 typedef __attribute__((__ext_vector_type__(64), __aligned__(1))) uint8_t packed_uchar64;
92
93 typedef __attribute__((__ext_vector_type__(4))) uint16_t vector_ushort4;
94 typedef __attribute__((__ext_vector_type__(4), __aligned__(2))) uint16_t packed_ushort4;
95
96 typedef __attribute__((__ext_vector_type__(2))) int32_t vector_int2;
97 typedef __attribute__((__ext_vector_type__(4))) int32_t vector_int4;
98 typedef __attribute__((__ext_vector_type__(8))) int32_t vector_int8;
99
100 typedef __attribute__((__ext_vector_type__(4))) uint32_t vector_uint4;
101
102 #define UTIL_FUNCTION static inline __attribute__((__always_inline__)) __attribute__((__overloadable__))
103
104 // Load N bytes from unaligned location PTR
105 UTIL_FUNCTION uint16_t
load2(const void * ptr)106 load2(const void * ptr)
107 {
108 uint16_t data; memcpy(&data, ptr, sizeof data); return data;
109 }
110 UTIL_FUNCTION uint32_t
load4(const void * ptr)111 load4(const void * ptr)
112 {
113 uint32_t data; memcpy(&data, ptr, sizeof data); return data;
114 }
115 UTIL_FUNCTION uint64_t
load8(const void * ptr)116 load8(const void * ptr)
117 {
118 uint64_t data; memcpy(&data, ptr, sizeof data); return data;
119 }
120 UTIL_FUNCTION vector_uchar16
load16(const void * ptr)121 load16(const void * ptr)
122 {
123 return (const vector_uchar16)*(const packed_uchar16 *)ptr;
124 }
125 UTIL_FUNCTION vector_uchar32
load32(const void * ptr)126 load32(const void * ptr)
127 {
128 return (const vector_uchar32)*(const packed_uchar32 *)ptr;
129 }
130 UTIL_FUNCTION vector_uchar64
load64(const void * ptr)131 load64(const void * ptr)
132 {
133 return (const vector_uchar64)*(const packed_uchar64 *)ptr;
134 }
135
136 // Store N bytes to unaligned location PTR
137 UTIL_FUNCTION void
store2(void * ptr,uint16_t data)138 store2(void * ptr, uint16_t data)
139 {
140 memcpy(ptr, &data, sizeof data);
141 }
142 UTIL_FUNCTION void
store4(void * ptr,uint32_t data)143 store4(void * ptr, uint32_t data)
144 {
145 memcpy(ptr, &data, sizeof data);
146 }
147 UTIL_FUNCTION void
store8(void * ptr,uint64_t data)148 store8(void * ptr, uint64_t data)
149 {
150 memcpy(ptr, &data, sizeof data);
151 }
152 UTIL_FUNCTION void
store16(void * ptr,vector_uchar16 data)153 store16(void * ptr, vector_uchar16 data)
154 {
155 *(packed_uchar16 *)ptr = (packed_uchar16)data;
156 }
157 UTIL_FUNCTION void
store32(void * ptr,vector_uchar32 data)158 store32(void * ptr, vector_uchar32 data)
159 {
160 *(packed_uchar32 *)ptr = (packed_uchar32)data;
161 }
162 UTIL_FUNCTION void
store64(void * ptr,vector_uchar64 data)163 store64(void * ptr, vector_uchar64 data)
164 {
165 *(packed_uchar64 *)ptr = (packed_uchar64)data;
166 }
167
168 // Load+Store N bytes from unaligned locations SRC to DST. No overlap allowed.
169 UTIL_FUNCTION void
copy8(void * dst,const void * src)170 copy8(void * dst, const void * src)
171 {
172 store8(dst, load8(src));
173 }
174 UTIL_FUNCTION void
copy16(void * dst,const void * src)175 copy16(void * dst, const void * src)
176 {
177 *(packed_uchar16 *)dst = *(const packed_uchar16 *)src;
178 }
179 UTIL_FUNCTION void
copy32(void * dst,const void * src)180 copy32(void * dst, const void * src)
181 {
182 *(packed_uchar32 *)dst = *(const packed_uchar32 *)src;
183 }
184
185 #undef memcpy
186