1 | /* |
2 | * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"). |
5 | * You may not use this file except in compliance with the License. |
6 | * A copy of the License is located at |
7 | * |
8 | * http://aws.amazon.com/apache2.0 |
9 | * |
10 | * or in the "license" file accompanying this file. This file is distributed |
11 | * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either |
12 | * express or implied. See the License for the specific language governing |
13 | * permissions and limitations under the License. |
14 | */ |
15 | |
16 | #include <aws/common/log_formatter.h> |
17 | |
18 | #include <aws/common/date_time.h> |
19 | #include <aws/common/string.h> |
20 | #include <aws/common/thread.h> |
21 | |
22 | #include <inttypes.h> |
23 | #include <stdarg.h> |
24 | |
25 | /* |
26 | * Default formatter implementation |
27 | */ |
28 | |
29 | #if _MSC_VER |
30 | # pragma warning(disable : 4204) /* non-constant aggregate initializer */ |
31 | #endif |
32 | |
33 | /* (max) strlen of "[<LogLevel>]" */ |
34 | #define LOG_LEVEL_PREFIX_PADDING 7 |
35 | |
36 | /* (max) strlen of "[<ThreadId>]" */ |
37 | #define THREAD_ID_PREFIX_PADDING 22 |
38 | |
39 | /* strlen of (user-content separator) " - " + "\n" + spaces between prefix fields + brackets around timestamp + 1 + |
40 | subject_name padding */ |
41 | #define MISC_PADDING 15 |
42 | |
43 | #define MAX_LOG_LINE_PREFIX_SIZE \ |
44 | (LOG_LEVEL_PREFIX_PADDING + THREAD_ID_PREFIX_PADDING + MISC_PADDING + AWS_DATE_TIME_STR_MAX_LEN) |
45 | |
46 | static size_t s_advance_and_clamp_index(size_t current_index, int amount, size_t maximum) { |
47 | size_t next_index = current_index + amount; |
48 | if (next_index > maximum) { |
49 | next_index = maximum; |
50 | } |
51 | |
52 | return next_index; |
53 | } |
54 | int aws_format_standard_log_line(struct aws_logging_standard_formatting_data *formatting_data, va_list args) { |
55 | size_t current_index = 0; |
56 | |
57 | /* |
58 | * Begin the log line with "[<Log Level>] [" |
59 | */ |
60 | const char *level_string = NULL; |
61 | if (aws_log_level_to_string(formatting_data->level, &level_string)) { |
62 | return AWS_OP_ERR; |
63 | } |
64 | |
65 | if (formatting_data->total_length == 0) { |
66 | return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT); |
67 | } |
68 | |
69 | /* |
70 | * Use this length for all but the last write, so we guarantee room for the newline even if we get truncated |
71 | */ |
72 | size_t fake_total_length = formatting_data->total_length - 1; |
73 | |
74 | int log_level_length = snprintf(formatting_data->log_line_buffer, fake_total_length, "[%s] [" , level_string); |
75 | if (log_level_length < 0) { |
76 | return AWS_OP_ERR; |
77 | } |
78 | |
79 | current_index = s_advance_and_clamp_index(current_index, log_level_length, fake_total_length); |
80 | |
81 | if (current_index < fake_total_length) { |
82 | /* |
83 | * Add the timestamp. To avoid copies and allocations, do some byte buffer tomfoolery. |
84 | * |
85 | * First, make a byte_buf that points to the current position in the output string |
86 | */ |
87 | struct aws_byte_buf timestamp_buffer = { |
88 | .allocator = formatting_data->allocator, |
89 | .buffer = (uint8_t *)formatting_data->log_line_buffer + current_index, |
90 | .capacity = fake_total_length - current_index, |
91 | .len = 0, |
92 | }; |
93 | |
94 | /* |
95 | * Output the current time to the byte_buf |
96 | */ |
97 | struct aws_date_time current_time; |
98 | aws_date_time_init_now(¤t_time); |
99 | |
100 | int result = aws_date_time_to_utc_time_str(¤t_time, formatting_data->date_format, ×tamp_buffer); |
101 | if (result != AWS_OP_SUCCESS) { |
102 | return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT); |
103 | } |
104 | |
105 | current_index = s_advance_and_clamp_index(current_index, (int)timestamp_buffer.len, fake_total_length); |
106 | } |
107 | |
108 | if (current_index < fake_total_length) { |
109 | /* |
110 | * Add thread id and user content separator (" - ") |
111 | */ |
112 | uint64_t current_thread_id = aws_thread_current_thread_id(); |
113 | int thread_id_written = snprintf( |
114 | formatting_data->log_line_buffer + current_index, |
115 | fake_total_length - current_index, |
116 | "] [%" PRIu64 "] " , |
117 | current_thread_id); |
118 | if (thread_id_written < 0) { |
119 | return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT); |
120 | } |
121 | |
122 | current_index = s_advance_and_clamp_index(current_index, thread_id_written, fake_total_length); |
123 | } |
124 | |
125 | if (current_index < fake_total_length) { |
126 | /* output subject name */ |
127 | if (formatting_data->subject_name) { |
128 | int subject_written = snprintf( |
129 | formatting_data->log_line_buffer + current_index, |
130 | fake_total_length - current_index, |
131 | "[%s]" , |
132 | formatting_data->subject_name); |
133 | |
134 | if (subject_written < 0) { |
135 | return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT); |
136 | } |
137 | |
138 | current_index = s_advance_and_clamp_index(current_index, subject_written, fake_total_length); |
139 | } |
140 | } |
141 | |
142 | if (current_index < fake_total_length) { |
143 | int separator_written = |
144 | snprintf(formatting_data->log_line_buffer + current_index, fake_total_length - current_index, " - " ); |
145 | current_index = s_advance_and_clamp_index(current_index, separator_written, fake_total_length); |
146 | } |
147 | |
148 | if (current_index < fake_total_length) { |
149 | /* |
150 | * Now write the actual data requested by the user |
151 | */ |
152 | #ifdef WIN32 |
153 | int written_count = vsnprintf_s( |
154 | formatting_data->log_line_buffer + current_index, |
155 | fake_total_length - current_index, |
156 | _TRUNCATE, |
157 | formatting_data->format, |
158 | args); |
159 | #else |
160 | int written_count = vsnprintf( |
161 | formatting_data->log_line_buffer + current_index, |
162 | fake_total_length - current_index, |
163 | formatting_data->format, |
164 | args); |
165 | #endif /* WIN32 */ |
166 | if (written_count < 0) { |
167 | return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT); |
168 | } |
169 | |
170 | current_index = s_advance_and_clamp_index(current_index, written_count, fake_total_length); |
171 | } |
172 | |
173 | /* |
174 | * End with a newline. |
175 | */ |
176 | int newline_written_count = |
177 | snprintf(formatting_data->log_line_buffer + current_index, formatting_data->total_length - current_index, "\n" ); |
178 | if (newline_written_count < 0) { |
179 | return aws_raise_error(AWS_ERROR_UNKNOWN); /* we saved space, so this would be crazy */ |
180 | } |
181 | |
182 | formatting_data->amount_written = current_index + newline_written_count; |
183 | |
184 | return AWS_OP_SUCCESS; |
185 | } |
186 | |
187 | struct aws_default_log_formatter_impl { |
188 | enum aws_date_format date_format; |
189 | }; |
190 | |
191 | static int s_default_aws_log_formatter_format( |
192 | struct aws_log_formatter *formatter, |
193 | struct aws_string **formatted_output, |
194 | enum aws_log_level level, |
195 | aws_log_subject_t subject, |
196 | const char *format, |
197 | va_list args) { |
198 | |
199 | (void)subject; |
200 | |
201 | struct aws_default_log_formatter_impl *impl = formatter->impl; |
202 | |
203 | if (formatted_output == NULL) { |
204 | return AWS_OP_ERR; |
205 | } |
206 | |
207 | /* |
208 | * Calculate how much room we'll need to build the full log line. |
209 | * You cannot consume a va_list twice, so we have to copy it. |
210 | */ |
211 | va_list tmp_args; |
212 | va_copy(tmp_args, args); |
213 | #ifdef WIN32 |
214 | int required_length = _vscprintf(format, tmp_args) + 1; |
215 | #else |
216 | int required_length = vsnprintf(NULL, 0, format, tmp_args) + 1; |
217 | #endif |
218 | va_end(tmp_args); |
219 | |
220 | /* |
221 | * Allocate enough room to hold the line. Then we'll (unsafely) do formatted IO directly into the aws_string |
222 | * memory. |
223 | */ |
224 | const char *subject_name = aws_log_subject_name(subject); |
225 | int subject_name_len = 0; |
226 | |
227 | if (subject_name) { |
228 | subject_name_len = (int)strlen(subject_name); |
229 | } |
230 | |
231 | int total_length = required_length + MAX_LOG_LINE_PREFIX_SIZE + subject_name_len; |
232 | struct aws_string *raw_string = aws_mem_calloc(formatter->allocator, 1, sizeof(struct aws_string) + total_length); |
233 | if (raw_string == NULL) { |
234 | goto error_clean_up; |
235 | } |
236 | |
237 | struct aws_logging_standard_formatting_data format_data = { |
238 | .log_line_buffer = (char *)raw_string->bytes, |
239 | .total_length = total_length, |
240 | .level = level, |
241 | .subject_name = subject_name, |
242 | .format = format, |
243 | .date_format = impl->date_format, |
244 | .allocator = formatter->allocator, |
245 | .amount_written = 0, |
246 | }; |
247 | |
248 | if (aws_format_standard_log_line(&format_data, args)) { |
249 | goto error_clean_up; |
250 | } |
251 | |
252 | *(struct aws_allocator **)(&raw_string->allocator) = formatter->allocator; |
253 | *(size_t *)(&raw_string->len) = format_data.amount_written; |
254 | |
255 | *formatted_output = raw_string; |
256 | |
257 | return AWS_OP_SUCCESS; |
258 | |
259 | error_clean_up: |
260 | |
261 | if (raw_string != NULL) { |
262 | aws_mem_release(formatter->allocator, raw_string); |
263 | } |
264 | |
265 | return AWS_OP_ERR; |
266 | } |
267 | |
268 | static void s_default_aws_log_formatter_clean_up(struct aws_log_formatter *formatter) { |
269 | aws_mem_release(formatter->allocator, formatter->impl); |
270 | } |
271 | |
272 | static struct aws_log_formatter_vtable s_default_log_formatter_vtable = { |
273 | .format = s_default_aws_log_formatter_format, |
274 | .clean_up = s_default_aws_log_formatter_clean_up, |
275 | }; |
276 | |
277 | int aws_log_formatter_init_default( |
278 | struct aws_log_formatter *formatter, |
279 | struct aws_allocator *allocator, |
280 | struct aws_log_formatter_standard_options *options) { |
281 | struct aws_default_log_formatter_impl *impl = |
282 | aws_mem_calloc(allocator, 1, sizeof(struct aws_default_log_formatter_impl)); |
283 | impl->date_format = options->date_format; |
284 | |
285 | formatter->vtable = &s_default_log_formatter_vtable; |
286 | formatter->allocator = allocator; |
287 | formatter->impl = impl; |
288 | |
289 | return AWS_OP_SUCCESS; |
290 | } |
291 | |
292 | void aws_log_formatter_clean_up(struct aws_log_formatter *formatter) { |
293 | AWS_ASSERT(formatter->vtable->clean_up); |
294 | (formatter->vtable->clean_up)(formatter); |
295 | } |
296 | |