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f3a3214e LT |
1 | #ifndef PKTLINE_H |
2 | #define PKTLINE_H | |
3 | ||
07d68930 | 4 | #include "git-compat-util.h" |
f5615d24 | 5 | #include "strbuf.h" |
07d68930 | 6 | |
f3a3214e | 7 | /* |
e1485428 JK |
8 | * Write a packetized stream, where each line is preceded by |
9 | * its length (including the header) as a 4-byte hex number. | |
10 | * A length of 'zero' means end of stream (and a length of 1-3 | |
11 | * would be an error). | |
12 | * | |
13 | * This is all pretty stupid, but we use this packetized line | |
14 | * format to make a streaming format possible without ever | |
15 | * over-running the read buffers. That way we'll never read | |
16 | * into what might be the pack data (which should go to another | |
17 | * process entirely). | |
18 | * | |
19 | * The writing side could use stdio, but since the reading | |
20 | * side can't, we stay with pure read/write interfaces. | |
f3a3214e LT |
21 | */ |
22 | void packet_flush(int fd); | |
a4cfd41c | 23 | void packet_delim(int fd); |
81c634e9 | 24 | void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3))); |
f5615d24 | 25 | void packet_buf_flush(struct strbuf *buf); |
a4cfd41c | 26 | void packet_buf_delim(struct strbuf *buf); |
5d2124b3 | 27 | void packet_write(int fd_out, const char *buf, size_t size); |
f5615d24 | 28 | void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3))); |
f1f4d8ac | 29 | void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len); |
038ce90f | 30 | int packet_flush_gently(int fd); |
70428d1a | 31 | int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3))); |
bb643d8b LS |
32 | int write_packetized_from_fd(int fd_in, int fd_out); |
33 | int write_packetized_from_buf(const char *src_in, size_t len, int fd_out); | |
f3a3214e | 34 | |
03809429 | 35 | /* |
4981fe75 JK |
36 | * Read a packetized line into the buffer, which must be at least size bytes |
37 | * long. The return value specifies the number of bytes read into the buffer. | |
38 | * | |
01689909 JL |
39 | * If src_buffer and *src_buffer are not NULL, it should point to a buffer |
40 | * containing the packet data to parse, of at least *src_len bytes. After the | |
41 | * function returns, src_buf will be incremented and src_len decremented by the | |
42 | * number of bytes consumed. | |
4981fe75 JK |
43 | * |
44 | * If src_buffer (or *src_buffer) is NULL, then data is read from the | |
45 | * descriptor "fd". | |
03809429 JK |
46 | * |
47 | * If options does not contain PACKET_READ_GENTLE_ON_EOF, we will die under any | |
48 | * of the following conditions: | |
49 | * | |
50 | * 1. Read error from descriptor. | |
51 | * | |
52 | * 2. Protocol error from the remote (e.g., bogus length characters). | |
53 | * | |
54 | * 3. Receiving a packet larger than "size" bytes. | |
55 | * | |
56 | * 4. Truncated output from the remote (e.g., we expected a packet but got | |
57 | * EOF, or we got a partial packet followed by EOF). | |
58 | * | |
59 | * If options does contain PACKET_READ_GENTLE_ON_EOF, we will not die on | |
60 | * condition 4 (truncated input), but instead return -1. However, we will still | |
61 | * die for the other 3 conditions. | |
819b929d JK |
62 | * |
63 | * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if | |
64 | * present) is removed from the buffer before returning. | |
03809429 JK |
65 | */ |
66 | #define PACKET_READ_GENTLE_ON_EOF (1u<<0) | |
819b929d | 67 | #define PACKET_READ_CHOMP_NEWLINE (1u<<1) |
4981fe75 JK |
68 | int packet_read(int fd, char **src_buffer, size_t *src_len, char |
69 | *buffer, unsigned size, int options); | |
03809429 | 70 | |
2153d478 BW |
71 | /* |
72 | * Read a packetized line into a buffer like the 'packet_read()' function but | |
73 | * returns an 'enum packet_read_status' which indicates the status of the read. | |
74 | * The number of bytes read will be assigined to *pktlen if the status of the | |
75 | * read was 'PACKET_READ_NORMAL'. | |
76 | */ | |
77 | enum packet_read_status { | |
78 | PACKET_READ_EOF, | |
79 | PACKET_READ_NORMAL, | |
80 | PACKET_READ_FLUSH, | |
a4cfd41c | 81 | PACKET_READ_DELIM, |
2153d478 BW |
82 | }; |
83 | enum packet_read_status packet_read_with_status(int fd, char **src_buffer, | |
84 | size_t *src_len, char *buffer, | |
85 | unsigned size, int *pktlen, | |
86 | int options); | |
87 | ||
819b929d JK |
88 | /* |
89 | * Convenience wrapper for packet_read that is not gentle, and sets the | |
74543a04 JK |
90 | * CHOMP_NEWLINE option. The return value is NULL for a flush packet, |
91 | * and otherwise points to a static buffer (that may be overwritten by | |
92 | * subsequent calls). If the size parameter is not NULL, the length of the | |
93 | * packet is written to it. | |
819b929d | 94 | */ |
74543a04 JK |
95 | char *packet_read_line(int fd, int *size); |
96 | ||
825b9226 BP |
97 | /* |
98 | * Convenience wrapper for packet_read that sets the PACKET_READ_GENTLE_ON_EOF | |
99 | * and CHOMP_NEWLINE options. The return value specifies the number of bytes | |
100 | * read into the buffer or -1 on truncated input. If the *dst_line parameter | |
101 | * is not NULL it will return NULL for a flush packet or when the number of | |
102 | * bytes copied is zero and otherwise points to a static buffer (that may be | |
103 | * overwritten by subsequent calls). If the size parameter is not NULL, the | |
104 | * length of the packet is written to it. | |
105 | */ | |
106 | int packet_read_line_gently(int fd, int *size, char **dst_line); | |
107 | ||
4981fe75 JK |
108 | /* |
109 | * Same as packet_read_line, but read from a buf rather than a descriptor; | |
110 | * see packet_read for details on how src_* is used. | |
111 | */ | |
112 | char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size); | |
03809429 | 113 | |
bb643d8b LS |
114 | /* |
115 | * Reads a stream of variable sized packets until a flush packet is detected. | |
116 | */ | |
117 | ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out); | |
118 | ||
77dabc14 BW |
119 | struct packet_reader { |
120 | /* source file descriptor */ | |
121 | int fd; | |
122 | ||
123 | /* source buffer and its size */ | |
124 | char *src_buffer; | |
125 | size_t src_len; | |
126 | ||
127 | /* buffer that pkt-lines are read into and its size */ | |
128 | char *buffer; | |
129 | unsigned buffer_size; | |
130 | ||
131 | /* options to be used during reads */ | |
132 | int options; | |
133 | ||
134 | /* status of the last read */ | |
135 | enum packet_read_status status; | |
136 | ||
137 | /* length of data read during the last read */ | |
138 | int pktlen; | |
139 | ||
140 | /* the last line read */ | |
141 | const char *line; | |
142 | ||
143 | /* indicates if a line has been peeked */ | |
144 | int line_peeked; | |
145 | }; | |
146 | ||
147 | /* | |
148 | * Initialize a 'struct packet_reader' object which is an | |
149 | * abstraction around the 'packet_read_with_status()' function. | |
150 | */ | |
151 | extern void packet_reader_init(struct packet_reader *reader, int fd, | |
152 | char *src_buffer, size_t src_len, | |
153 | int options); | |
154 | ||
155 | /* | |
156 | * Perform a packet read and return the status of the read. | |
157 | * The values of 'pktlen' and 'line' are updated based on the status of the | |
158 | * read as follows: | |
159 | * | |
160 | * PACKET_READ_ERROR: 'pktlen' is set to '-1' and 'line' is set to NULL | |
161 | * PACKET_READ_NORMAL: 'pktlen' is set to the number of bytes read | |
162 | * 'line' is set to point at the read line | |
163 | * PACKET_READ_FLUSH: 'pktlen' is set to '0' and 'line' is set to NULL | |
164 | */ | |
165 | extern enum packet_read_status packet_reader_read(struct packet_reader *reader); | |
166 | ||
167 | /* | |
168 | * Peek the next packet line without consuming it and return the status. | |
169 | * The next call to 'packet_reader_read()' will perform a read of the same line | |
170 | * that was peeked, consuming the line. | |
171 | * | |
172 | * Peeking multiple times without calling 'packet_reader_read()' will return | |
173 | * the same result. | |
174 | */ | |
175 | extern enum packet_read_status packet_reader_peek(struct packet_reader *reader); | |
176 | ||
047ec602 JK |
177 | #define DEFAULT_PACKET_MAX 1000 |
178 | #define LARGE_PACKET_MAX 65520 | |
bb643d8b | 179 | #define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4) |
74543a04 | 180 | extern char packet_buffer[LARGE_PACKET_MAX]; |
047ec602 | 181 | |
f3a3214e | 182 | #endif |