diff options
Diffstat (limited to 'daemon/DynBuf.cpp')
-rw-r--r-- | daemon/DynBuf.cpp | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/daemon/DynBuf.cpp b/daemon/DynBuf.cpp new file mode 100644 index 0000000..6f92b33 --- /dev/null +++ b/daemon/DynBuf.cpp | |||
@@ -0,0 +1,139 @@ | |||
1 | /** | ||
2 | * Copyright (C) ARM Limited 2013-2014. All rights reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License version 2 as | ||
6 | * published by the Free Software Foundation. | ||
7 | */ | ||
8 | |||
9 | #include "DynBuf.h" | ||
10 | |||
11 | #include <errno.h> | ||
12 | #include <fcntl.h> | ||
13 | #include <stdarg.h> | ||
14 | #include <stdio.h> | ||
15 | #include <unistd.h> | ||
16 | |||
17 | #include "Logging.h" | ||
18 | |||
19 | // Pick an aggressive size as buffer is primarily used for disk IO | ||
20 | #define MIN_BUFFER_FREE (1 << 12) | ||
21 | |||
22 | int DynBuf::resize(const size_t minCapacity) { | ||
23 | size_t scaledCapacity = 2 * capacity; | ||
24 | if (scaledCapacity < minCapacity) { | ||
25 | scaledCapacity = minCapacity; | ||
26 | } | ||
27 | if (scaledCapacity < 2 * MIN_BUFFER_FREE) { | ||
28 | scaledCapacity = 2 * MIN_BUFFER_FREE; | ||
29 | } | ||
30 | capacity = scaledCapacity; | ||
31 | |||
32 | buf = static_cast<char *>(realloc(buf, capacity)); | ||
33 | if (buf == NULL) { | ||
34 | return -errno; | ||
35 | } | ||
36 | |||
37 | return 0; | ||
38 | } | ||
39 | |||
40 | bool DynBuf::read(const char *const path) { | ||
41 | int result = false; | ||
42 | |||
43 | const int fd = open(path, O_RDONLY); | ||
44 | if (fd < 0) { | ||
45 | logg->logMessage("%s(%s:%i): open failed", __FUNCTION__, __FILE__, __LINE__); | ||
46 | return false; | ||
47 | } | ||
48 | |||
49 | length = 0; | ||
50 | |||
51 | for (;;) { | ||
52 | const size_t minCapacity = length + MIN_BUFFER_FREE + 1; | ||
53 | if (capacity < minCapacity) { | ||
54 | if (resize(minCapacity) != 0) { | ||
55 | logg->logMessage("%s(%s:%i): DynBuf::resize failed", __FUNCTION__, __FILE__, __LINE__); | ||
56 | goto fail; | ||
57 | } | ||
58 | } | ||
59 | |||
60 | const ssize_t bytes = ::read(fd, buf + length, capacity - length - 1); | ||
61 | if (bytes < 0) { | ||
62 | logg->logMessage("%s(%s:%i): read failed", __FUNCTION__, __FILE__, __LINE__); | ||
63 | goto fail; | ||
64 | } else if (bytes == 0) { | ||
65 | break; | ||
66 | } | ||
67 | length += bytes; | ||
68 | } | ||
69 | |||
70 | buf[length] = '\0'; | ||
71 | result = true; | ||
72 | |||
73 | fail: | ||
74 | close(fd); | ||
75 | |||
76 | return result; | ||
77 | } | ||
78 | |||
79 | int DynBuf::readlink(const char *const path) { | ||
80 | ssize_t bytes = MIN_BUFFER_FREE; | ||
81 | |||
82 | for (;;) { | ||
83 | if (static_cast<size_t>(bytes) >= capacity) { | ||
84 | const int err = resize(2 * bytes); | ||
85 | if (err != 0) { | ||
86 | return err; | ||
87 | } | ||
88 | } | ||
89 | bytes = ::readlink(path, buf, capacity); | ||
90 | if (bytes < 0) { | ||
91 | return -errno; | ||
92 | } else if (static_cast<size_t>(bytes) < capacity) { | ||
93 | break; | ||
94 | } | ||
95 | } | ||
96 | |||
97 | length = bytes; | ||
98 | buf[bytes] = '\0'; | ||
99 | |||
100 | return 0; | ||
101 | } | ||
102 | |||
103 | bool DynBuf::printf(const char *format, ...) { | ||
104 | va_list ap; | ||
105 | |||
106 | if (capacity <= 0) { | ||
107 | if (resize(2 * MIN_BUFFER_FREE) != 0) { | ||
108 | logg->logMessage("%s(%s:%i): DynBuf::resize failed", __FUNCTION__, __FILE__, __LINE__); | ||
109 | return false; | ||
110 | } | ||
111 | } | ||
112 | |||
113 | va_start(ap, format); | ||
114 | int bytes = vsnprintf(buf, capacity, format, ap); | ||
115 | va_end(ap); | ||
116 | if (bytes < 0) { | ||
117 | logg->logMessage("%s(%s:%i): fsnprintf failed", __FUNCTION__, __FILE__, __LINE__); | ||
118 | return false; | ||
119 | } | ||
120 | |||
121 | if (static_cast<size_t>(bytes) > capacity) { | ||
122 | if (resize(bytes + 1) != 0) { | ||
123 | logg->logMessage("%s(%s:%i): DynBuf::resize failed", __FUNCTION__, __FILE__, __LINE__); | ||
124 | return false; | ||
125 | } | ||
126 | |||
127 | va_start(ap, format); | ||
128 | bytes = vsnprintf(buf, capacity, format, ap); | ||
129 | va_end(ap); | ||
130 | if (bytes < 0) { | ||
131 | logg->logMessage("%s(%s:%i): fsnprintf failed", __FUNCTION__, __FILE__, __LINE__); | ||
132 | return false; | ||
133 | } | ||
134 | } | ||
135 | |||
136 | length = bytes; | ||
137 | |||
138 | return true; | ||
139 | } | ||