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author | Elliott Hughes | 2017-11-10 12:22:07 -0600 |
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committer | Elliott Hughes | 2017-11-10 15:18:10 -0600 |
commit | 8e9aeb9053695a14539653093937158d15385ca6 (patch) | |
tree | b02f7ad2149812eea2cb2802b7f238856b66619c /libcutils/record_stream.cpp | |
parent | 6707ef139d9786887649e3e3c2e3e251a95dc96d (diff) | |
download | platform-system-core-8e9aeb9053695a14539653093937158d15385ca6.tar.gz platform-system-core-8e9aeb9053695a14539653093937158d15385ca6.tar.xz platform-system-core-8e9aeb9053695a14539653093937158d15385ca6.zip |
Move libcutils source to C++.
Just the minimial changes to get this to actually build, because otherwise
we always bog down trying to rewrite everything (when the real answer
is usually "stop using libcutils, it's awful").
This doesn't move a handful of files: two are basically just BSD libc
source, a couple have outstanding code reviews, and one can be deleted
(but I'll do that in a separate change).
I'm also skipping the presubmit hooks because otherwise clang-format
wants to reformat everything. I'll follow up with that...
Bug: N/A
Test: builds
Change-Id: I06403f465b67c8e493bad466dd76b1151eed5993
Diffstat (limited to 'libcutils/record_stream.cpp')
-rw-r--r-- | libcutils/record_stream.cpp | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/libcutils/record_stream.cpp b/libcutils/record_stream.cpp new file mode 100644 index 000000000..5a86b8393 --- /dev/null +++ b/libcutils/record_stream.cpp | |||
@@ -0,0 +1,187 @@ | |||
1 | /* libs/cutils/record_stream.c | ||
2 | ** | ||
3 | ** Copyright 2006, The Android Open Source Project | ||
4 | ** | ||
5 | ** Licensed under the Apache License, Version 2.0 (the "License"); | ||
6 | ** you may not use this file except in compliance with the License. | ||
7 | ** You may obtain a copy of the License at | ||
8 | ** | ||
9 | ** http://www.apache.org/licenses/LICENSE-2.0 | ||
10 | ** | ||
11 | ** Unless required by applicable law or agreed to in writing, software | ||
12 | ** distributed under the License is distributed on an "AS IS" BASIS, | ||
13 | ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
14 | ** See the License for the specific language governing permissions and | ||
15 | ** limitations under the License. | ||
16 | */ | ||
17 | |||
18 | #include <cutils/record_stream.h> | ||
19 | |||
20 | #include <stdlib.h> | ||
21 | #include <unistd.h> | ||
22 | #include <assert.h> | ||
23 | #include <errno.h> | ||
24 | #include <string.h> | ||
25 | #include <stdint.h> | ||
26 | #if defined(_WIN32) | ||
27 | #include <winsock2.h> /* for ntohl */ | ||
28 | #else | ||
29 | #include <netinet/in.h> | ||
30 | #endif | ||
31 | |||
32 | #define HEADER_SIZE 4 | ||
33 | |||
34 | struct RecordStream { | ||
35 | int fd; | ||
36 | size_t maxRecordLen; | ||
37 | |||
38 | unsigned char *buffer; | ||
39 | |||
40 | unsigned char *unconsumed; | ||
41 | unsigned char *read_end; | ||
42 | unsigned char *buffer_end; | ||
43 | }; | ||
44 | |||
45 | |||
46 | extern RecordStream *record_stream_new(int fd, size_t maxRecordLen) | ||
47 | { | ||
48 | RecordStream *ret; | ||
49 | |||
50 | assert (maxRecordLen <= 0xffff); | ||
51 | |||
52 | ret = (RecordStream *)calloc(1, sizeof(RecordStream)); | ||
53 | |||
54 | ret->fd = fd; | ||
55 | ret->maxRecordLen = maxRecordLen; | ||
56 | ret->buffer = (unsigned char *)malloc (maxRecordLen + HEADER_SIZE); | ||
57 | |||
58 | ret->unconsumed = ret->buffer; | ||
59 | ret->read_end = ret->buffer; | ||
60 | ret->buffer_end = ret->buffer + maxRecordLen + HEADER_SIZE; | ||
61 | |||
62 | return ret; | ||
63 | } | ||
64 | |||
65 | |||
66 | extern void record_stream_free(RecordStream *rs) | ||
67 | { | ||
68 | free(rs->buffer); | ||
69 | free(rs); | ||
70 | } | ||
71 | |||
72 | |||
73 | /* returns NULL; if there isn't a full record in the buffer */ | ||
74 | static unsigned char * getEndOfRecord (unsigned char *p_begin, | ||
75 | unsigned char *p_end) | ||
76 | { | ||
77 | size_t len; | ||
78 | unsigned char * p_ret; | ||
79 | |||
80 | if (p_end < p_begin + HEADER_SIZE) { | ||
81 | return NULL; | ||
82 | } | ||
83 | |||
84 | //First four bytes are length | ||
85 | len = ntohl(*((uint32_t *)p_begin)); | ||
86 | |||
87 | p_ret = p_begin + HEADER_SIZE + len; | ||
88 | |||
89 | if (p_end < p_ret) { | ||
90 | return NULL; | ||
91 | } | ||
92 | |||
93 | return p_ret; | ||
94 | } | ||
95 | |||
96 | static void *getNextRecord (RecordStream *p_rs, size_t *p_outRecordLen) | ||
97 | { | ||
98 | unsigned char *record_start, *record_end; | ||
99 | |||
100 | record_end = getEndOfRecord (p_rs->unconsumed, p_rs->read_end); | ||
101 | |||
102 | if (record_end != NULL) { | ||
103 | /* one full line in the buffer */ | ||
104 | record_start = p_rs->unconsumed + HEADER_SIZE; | ||
105 | p_rs->unconsumed = record_end; | ||
106 | |||
107 | *p_outRecordLen = record_end - record_start; | ||
108 | |||
109 | return record_start; | ||
110 | } | ||
111 | |||
112 | return NULL; | ||
113 | } | ||
114 | |||
115 | /** | ||
116 | * Reads the next record from stream fd | ||
117 | * Records are prefixed by a 16-bit big endian length value | ||
118 | * Records may not be larger than maxRecordLen | ||
119 | * | ||
120 | * Doesn't guard against EINTR | ||
121 | * | ||
122 | * p_outRecord and p_outRecordLen may not be NULL | ||
123 | * | ||
124 | * Return 0 on success, -1 on fail | ||
125 | * Returns 0 with *p_outRecord set to NULL on end of stream | ||
126 | * Returns -1 / errno = EAGAIN if it needs to read again | ||
127 | */ | ||
128 | int record_stream_get_next (RecordStream *p_rs, void ** p_outRecord, | ||
129 | size_t *p_outRecordLen) | ||
130 | { | ||
131 | void *ret; | ||
132 | |||
133 | ssize_t countRead; | ||
134 | |||
135 | /* is there one record already in the buffer? */ | ||
136 | ret = getNextRecord (p_rs, p_outRecordLen); | ||
137 | |||
138 | if (ret != NULL) { | ||
139 | *p_outRecord = ret; | ||
140 | return 0; | ||
141 | } | ||
142 | |||
143 | // if the buffer is full and we don't have a full record | ||
144 | if (p_rs->unconsumed == p_rs->buffer | ||
145 | && p_rs->read_end == p_rs->buffer_end | ||
146 | ) { | ||
147 | // this should never happen | ||
148 | //ALOGE("max record length exceeded\n"); | ||
149 | assert (0); | ||
150 | errno = EFBIG; | ||
151 | return -1; | ||
152 | } | ||
153 | |||
154 | if (p_rs->unconsumed != p_rs->buffer) { | ||
155 | // move remainder to the beginning of the buffer | ||
156 | size_t toMove; | ||
157 | |||
158 | toMove = p_rs->read_end - p_rs->unconsumed; | ||
159 | if (toMove) { | ||
160 | memmove(p_rs->buffer, p_rs->unconsumed, toMove); | ||
161 | } | ||
162 | |||
163 | p_rs->read_end = p_rs->buffer + toMove; | ||
164 | p_rs->unconsumed = p_rs->buffer; | ||
165 | } | ||
166 | |||
167 | countRead = read (p_rs->fd, p_rs->read_end, p_rs->buffer_end - p_rs->read_end); | ||
168 | |||
169 | if (countRead <= 0) { | ||
170 | /* note: end-of-stream drops through here too */ | ||
171 | *p_outRecord = NULL; | ||
172 | return countRead; | ||
173 | } | ||
174 | |||
175 | p_rs->read_end += countRead; | ||
176 | |||
177 | ret = getNextRecord (p_rs, p_outRecordLen); | ||
178 | |||
179 | if (ret == NULL) { | ||
180 | /* not enough of a buffer to for a whole command */ | ||
181 | errno = EAGAIN; | ||
182 | return -1; | ||
183 | } | ||
184 | |||
185 | *p_outRecord = ret; | ||
186 | return 0; | ||
187 | } | ||