projects/guix·blob python-team · refs

132 lines · 3.2 KiB

1#pragma once
2
3#include "types.hh"
4
5
6namespace nix {
7
8
9/* Abstract destination of binary data. */
10struct Sink
11{
12 virtual ~Sink() { }
13 virtual void operator () (const unsigned char * data, size_t len) = 0;
14};
15
16
17/* A buffered abstract sink. */
18struct BufferedSink : Sink
19{
20 size_t bufSize, bufPos;
21 unsigned char * buffer;
22
23 BufferedSink(size_t bufSize = 32 * 1024)
24 : bufSize(bufSize), bufPos(0), buffer(0) { }
25 ~BufferedSink();
26
27 void operator () (const unsigned char * data, size_t len);
28
29 void flush();
30
31 virtual void write(const unsigned char * data, size_t len) = 0;
32};
33
34
35/* Abstract source of binary data. */
36struct Source
37{
38 virtual ~Source() { }
39
40 /* Store exactly ‘len’ bytes in the buffer pointed to by ‘data’.
41 It blocks until all the requested data is available, or throws
42 an error if it is not going to be available. */
43 void operator () (unsigned char * data, size_t len);
44
45 /* Store up to ‘len’ in the buffer pointed to by ‘data’, and
46 return the number of bytes stored. If blocks until at least
47 one byte is available. */
48 virtual size_t read(unsigned char * data, size_t len) = 0;
49};
50
51
52/* A buffered abstract source. */
53struct BufferedSource : Source
54{
55 size_t bufSize, bufPosIn, bufPosOut;
56 unsigned char * buffer;
57
58 BufferedSource(size_t bufSize = 32 * 1024)
59 : bufSize(bufSize), bufPosIn(0), bufPosOut(0), buffer(0) { }
60 ~BufferedSource();
61
62 size_t read(unsigned char * data, size_t len);
63
64 /* Underlying read call, to be overridden. */
65 virtual size_t readUnbuffered(unsigned char * data, size_t len) = 0;
66
67 bool hasData();
68};
69
70
71/* A sink that writes data to a file descriptor. */
72struct FdSink : BufferedSink
73{
74 int fd;
75 bool warn;
76 size_t written;
77
78 FdSink() : fd(-1), warn(false), written(0) { }
79 FdSink(int fd) : fd(fd), warn(false), written(0) { }
80 ~FdSink();
81
82 void write(const unsigned char * data, size_t len);
83};
84
85
86/* A source that reads data from a file descriptor. */
87struct FdSource : BufferedSource
88{
89 int fd;
90 FdSource() : fd(-1) { }
91 FdSource(int fd) : fd(fd) { }
92 size_t readUnbuffered(unsigned char * data, size_t len);
93};
94
95
96/* A sink that writes data to a string. */
97struct StringSink : Sink
98{
99 string s;
100 void operator () (const unsigned char * data, size_t len);
101};
102
103
104/* A source that reads data from a string. */
105struct StringSource : Source
106{
107 const string & s;
108 size_t pos;
109 StringSource(const string & _s) : s(_s), pos(0) { }
110 size_t read(unsigned char * data, size_t len);
111};
112
113
114void writePadding(size_t len, Sink & sink);
115void writeInt(unsigned int n, Sink & sink);
116void writeLongLong(unsigned long long n, Sink & sink);
117void writeString(const unsigned char * buf, size_t len, Sink & sink);
118void writeString(const string & s, Sink & sink);
119template<class T> void writeStrings(const T & ss, Sink & sink);
120
121void readPadding(size_t len, Source & source);
122unsigned int readInt(Source & source);
123unsigned long long readLongLong(Source & source);
124size_t readString(unsigned char * buf, size_t max, Source & source);
125string readString(Source & source);
126template<class T> T readStrings(Source & source);
127
128
129MakeError(SerialisationError, Error)
130
131
132}