1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
2 // vim: ts=8 sw=2 smarttab
3 /*
4 * Ceph - scalable distributed file system
5 *
6 * Copyright (C) 2017 Haomai Wang <haomaiwang@gmail.com>
7 *
8 * This is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License version 2.1, as published by the Free Software
11 * Foundation. See file COPYING.
12 *
13 */
14
15 #ifndef CEPH_LZ4COMPRESSOR_H
16 #define CEPH_LZ4COMPRESSOR_H
17
18 #include <lz4.h>
19
20 #include "compressor/Compressor.h"
21 #include "include/buffer.h"
22 #include "include/encoding.h"
23 #include "common/config.h"
24 #include "common/Tub.h"
25
26
27 class LZ4Compressor : public Compressor {
28 public:
29 LZ4Compressor(CephContext* cct) : Compressor(COMP_ALG_LZ4, "lz4") {
30 #ifdef HAVE_QATZIP
31 if (cct->_conf->qat_compressor_enabled && qat_accel.init("lz4"))
32 qat_enabled = true;
33 else
34 qat_enabled = false;
35 #endif
36 }
37
38 int compress(const bufferlist &src, bufferlist &dst) override {
39 #ifdef HAVE_QATZIP
40 if (qat_enabled)
41 return qat_accel.compress(src, dst);
42 #endif
43 bufferptr outptr = buffer::create_small_page_aligned(
44 LZ4_compressBound(src.length()));
|
(1) Event stack_use_local_overflow: |
Local variable "lz4_stream" uses 16416 bytes of stack space, which exceeds the maximum single use of 10000 bytes. |
45 LZ4_stream_t lz4_stream;
46 LZ4_resetStream(&lz4_stream);
47
48 auto p = src.begin();
49 size_t left = src.length();
50 int pos = 0;
51 const char *data;
52 unsigned num = src.get_num_buffers();
53 encode((uint32_t)num, dst);
54 while (left) {
55 uint32_t origin_len = p.get_ptr_and_advance(left, &data);
56 int compressed_len = LZ4_compress_fast_continue(
57 &lz4_stream, data, outptr.c_str()+pos, origin_len,
58 outptr.length()-pos, 1);
59 if (compressed_len <= 0)
60 return -1;
61 pos += compressed_len;
62 left -= origin_len;
63 encode(origin_len, dst);
64 encode((uint32_t)compressed_len, dst);
65 }
66 ceph_assert(p.end());
67
68 dst.append(outptr, 0, pos);
69 return 0;
70 }
71
72 int decompress(const bufferlist &src, bufferlist &dst) override {
73 #ifdef HAVE_QATZIP
74 if (qat_enabled)
75 return qat_accel.decompress(src, dst);
76 #endif
77 auto i = std::cbegin(src);
78 return decompress(i, src.length(), dst);
79 }
80
81 int decompress(bufferlist::const_iterator &p,
82 size_t compressed_len,
83 bufferlist &dst) override {
84 #ifdef HAVE_QATZIP
85 if (qat_enabled)
86 return qat_accel.decompress(p, compressed_len, dst);
87 #endif
88 uint32_t count;
89 std::vector<std::pair<uint32_t, uint32_t> > compressed_pairs;
90 decode(count, p);
91 compressed_pairs.resize(count);
92 uint32_t total_origin = 0;
93 for (unsigned i = 0; i < count; ++i) {
94 decode(compressed_pairs[i].first, p);
95 decode(compressed_pairs[i].second, p);
96 total_origin += compressed_pairs[i].first;
97 }
98 compressed_len -= (sizeof(uint32_t) + sizeof(uint32_t) * count * 2);
99
100 bufferptr dstptr(total_origin);
101 LZ4_streamDecode_t lz4_stream_decode;
102 LZ4_setStreamDecode(&lz4_stream_decode, nullptr, 0);
103
104 bufferptr cur_ptr = p.get_current_ptr();
105 bufferptr *ptr = &cur_ptr;
106 Tub<bufferptr> data_holder;
107 if (compressed_len != cur_ptr.length()) {
108 data_holder.construct(compressed_len);
109 p.copy_deep(compressed_len, *data_holder);
110 ptr = data_holder.get();
111 }
112
113 char *c_in = ptr->c_str();
114 char *c_out = dstptr.c_str();
115 for (unsigned i = 0; i < count; ++i) {
116 int r = LZ4_decompress_safe_continue(
117 &lz4_stream_decode, c_in, c_out, compressed_pairs[i].second, compressed_pairs[i].first);
118 if (r == (int)compressed_pairs[i].first) {
119 c_in += compressed_pairs[i].second;
120 c_out += compressed_pairs[i].first;
121 } else if (r < 0) {
122 return -1;
123 } else {
124 return -2;
125 }
126 }
127 dst.push_back(std::move(dstptr));
128 return 0;
129 }
130 };
131
132 #endif
133