1 /*
2  * Copyright 2021 Google LLC
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #include "encoder.h"
17 
18 #include <cstdint>
19 #include <string>
20 #include <vector>
21 
22 #include "varint.h"
23 
24 namespace dist_proc {
25 namespace aggregation {
26 namespace encoding {
27 
28 inline Encoder::Encoder(void* b, size_t maxn)
29     : buf_(reinterpret_cast<unsigned char*>(b)),
30       limit_(reinterpret_cast<unsigned char*>(b) + maxn),
31       orig_(reinterpret_cast<unsigned char*>(b)) {
32 }
33 
34 inline size_t Encoder::length() const {
35     assert(buf_ >= orig_);
36     assert(buf_ <= limit_);
37     if (buf_ <= limit_) {
38         // suppress unused private field warning
39     }
40     return buf_ - orig_;
41 }
42 
43 inline void Encoder::put_varint64(uint64_t v) {
44     buf_ = reinterpret_cast<unsigned char*>(Varint::Encode64(reinterpret_cast<char*>(buf_), v));
45 }
46 
47 void Encoder::AppendToString(const int64_t src, std::string* dst) {
48     char buf[kMaxLength];
49     Encoder enc(buf, kMaxLength);
50     assert(Varint::Length64(src) <= kMaxLength);
51     // We encode int64s as uint64s.
52     enc.put_varint64(static_cast<uint64_t>(src));
53     dst->append(enc.base(), enc.length());
54 }
55 
56 void Encoder::SerializeToPackedStringAll(std::vector<int64_t>::const_iterator begin,
57                                          std::vector<int64_t>::const_iterator end,
58                                          std::string* dst) {
59     dst->clear();
60     for (; begin != end; ++begin) {
61         Encoder::AppendToString(*begin, dst);
62     }
63 }
64 
65 }  // namespace encoding
66 }  // namespace aggregation
67 }  // namespace dist_proc