1 | /* Copyright 2015 The TensorFlow Authors. All Rights Reserved. |
2 | |
3 | Licensed under the Apache License, Version 2.0 (the "License"); |
4 | you may not use this file except in compliance with the License. |
5 | You may obtain a copy of the License at |
6 | |
7 | http://www.apache.org/licenses/LICENSE-2.0 |
8 | |
9 | Unless required by applicable law or agreed to in writing, software |
10 | distributed under the License is distributed on an "AS IS" BASIS, |
11 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | See the License for the specific language governing permissions and |
13 | limitations under the License. |
14 | ==============================================================================*/ |
15 | |
16 | // Helper routines for encoding/decoding tensor contents. |
17 | #ifndef TENSORFLOW_CORE_PLATFORM_TENSOR_CODING_H_ |
18 | #define TENSORFLOW_CORE_PLATFORM_TENSOR_CODING_H_ |
19 | |
20 | #include <string> |
21 | |
22 | #include "tensorflow/core/platform/platform.h" |
23 | #include "tensorflow/core/platform/protobuf.h" |
24 | #include "tensorflow/core/platform/refcount.h" |
25 | #include "tensorflow/core/platform/stringpiece.h" |
26 | #include "tensorflow/core/platform/types.h" |
27 | |
28 | namespace tensorflow { |
29 | namespace port { |
30 | |
31 | // Store src contents in *out. If backing memory for src is shared with *out, |
32 | // will ref obj during the call and will arrange to unref obj when no |
33 | // longer needed. |
34 | void AssignRefCounted(StringPiece src, core::RefCounted* obj, std::string* out); |
35 | |
36 | // Copy contents of src to dst[0,src.size()-1]. |
37 | inline void CopyToArray(const std::string& src, char* dst) { |
38 | memcpy(dst, src.data(), src.size()); |
39 | } |
40 | |
41 | // Copy subrange [pos:(pos + n)) from src to dst. If pos >= src.size() the |
42 | // result is empty. If pos + n > src.size() the subrange [pos, size()) is |
43 | // copied. |
44 | inline void CopySubrangeToArray(const std::string& src, size_t pos, size_t n, |
45 | char* dst) { |
46 | if (pos >= src.size()) return; |
47 | memcpy(dst, src.data() + pos, std::min(n, src.size() - pos)); |
48 | } |
49 | |
50 | // Store encoding of strings[0..n-1] in *out. |
51 | void EncodeStringList(const tstring* strings, int64_t n, std::string* out); |
52 | |
53 | // Decode n strings from src and store in strings[0..n-1]. |
54 | // Returns true if successful, false on parse error. |
55 | bool DecodeStringList(const std::string& src, tstring* strings, int64_t n); |
56 | |
57 | // Assigns base[0..bytes-1] to *s |
58 | void CopyFromArray(std::string* s, const char* base, size_t bytes); |
59 | |
60 | // Encodes sequences of strings and serialized protocol buffers into a string. |
61 | // Normal usage consists of zero or more calls to Append() and a single call to |
62 | // Finalize(). |
63 | class StringListEncoder { |
64 | public: |
65 | virtual ~StringListEncoder() = default; |
66 | |
67 | // Encodes the given protocol buffer. This may not be called after Finalize(). |
68 | virtual void Append(const protobuf::MessageLite& m) = 0; |
69 | |
70 | // Encodes the given string. This may not be called after Finalize(). |
71 | virtual void Append(const std::string& s) = 0; |
72 | |
73 | // Signals end of the encoding process. No other calls are allowed after this. |
74 | virtual void Finalize() = 0; |
75 | }; |
76 | |
77 | // Decodes a string into sequences of strings (which may represent serialized |
78 | // protocol buffers). Normal usage involves a single call to ReadSizes() in |
79 | // order to retrieve the length of all the strings in the sequence. For each |
80 | // size returned a call to Data() is expected and will return the actual |
81 | // string. |
82 | class StringListDecoder { |
83 | public: |
84 | virtual ~StringListDecoder() = default; |
85 | |
86 | // Populates the given vector with the lengths of each string in the sequence |
87 | // being decoded. Upon returning the vector is guaranteed to contain as many |
88 | // elements as there are strings in the sequence. |
89 | virtual bool ReadSizes(std::vector<uint32>* sizes) = 0; |
90 | |
91 | // Returns a pointer to the next string in the sequence, then prepares for the |
92 | // next call by advancing 'size' characters in the sequence. |
93 | virtual const char* Data(uint32 size) = 0; |
94 | }; |
95 | |
96 | std::unique_ptr<StringListEncoder> NewStringListEncoder(string* out); |
97 | std::unique_ptr<StringListDecoder> NewStringListDecoder(const string& in); |
98 | |
99 | #if defined(TENSORFLOW_PROTOBUF_USES_CORD) |
100 | // Store src contents in *out. If backing memory for src is shared with *out, |
101 | // will ref obj during the call and will arrange to unref obj when no |
102 | // longer needed. |
103 | void AssignRefCounted(StringPiece src, core::RefCounted* obj, absl::Cord* out); |
104 | |
105 | // TODO(kmensah): Macro guard this with a check for Cord support. |
106 | inline void CopyToArray(const absl::Cord& src, char* dst) { |
107 | src.CopyToArray(dst); |
108 | } |
109 | |
110 | // Copy n bytes of src to dst. If pos >= src.size() the result is empty. |
111 | // If pos + n > src.size() the subrange [pos, size()) is copied. |
112 | inline void CopySubrangeToArray(const absl::Cord& src, int64_t pos, int64_t n, |
113 | char* dst) { |
114 | src.Subcord(pos, n).CopyToArray(dst); |
115 | } |
116 | |
117 | // Store encoding of strings[0..n-1] in *out. |
118 | void EncodeStringList(const tstring* strings, int64_t n, absl::Cord* out); |
119 | |
120 | // Decode n strings from src and store in strings[0..n-1]. |
121 | // Returns true if successful, false on parse error. |
122 | bool DecodeStringList(const absl::Cord& src, std::string* strings, int64_t n); |
123 | bool DecodeStringList(const absl::Cord& src, tstring* strings, int64_t n); |
124 | |
125 | // Assigns base[0..bytes-1] to *c |
126 | void CopyFromArray(absl::Cord* c, const char* base, size_t bytes); |
127 | |
128 | std::unique_ptr<StringListEncoder> NewStringListEncoder(absl::Cord* out); |
129 | std::unique_ptr<StringListDecoder> NewStringListDecoder(const absl::Cord& in); |
130 | #endif // defined(TENSORFLOW_PROTOBUF_USES_CORD) |
131 | |
132 | } // namespace port |
133 | } // namespace tensorflow |
134 | |
135 | #endif // TENSORFLOW_CORE_PLATFORM_TENSOR_CODING_H_ |
136 | |