上次说到了是如何缓存到本地的，那么缓存到本地就应该使用了吧。在start_capture对应的就是start_playback
193void start_playback(char *pkg_name_arg) {
...
216 if(pthread_create(&start_playback_pthread_id, NULL, start_playback_thread, pkg_name)) {
217 return ;
218 }
219 QLOGI("Exit playback");
220 return ;
221}
创建一个线程来进行操作
56void* start_playback_thread(void *pkg_name_arg)
57{
58 file_details *file_detail_ptr;
59 int num_file = 0;
60 int num_of_files = 0;
61 char *pkg_name = (char *)pkg_name_arg;
62 int i = 0;
63 int total_data = 0;
64 struct stat file_stat;
65 ATRACE_BEGIN("start_playback_thread: Enter");
66
67 QLOGI("pkg_name = %s",pkg_name);
68 num_file = get_total_file(pkg_name);
69
70 if( num_file <= 0)
71 {
72 QLOGI("no file to read get_total_file %d", num_file);
73 remove_pkg(pkg_name);
74 free(pkg_name);
75 ATRACE_END();
76 return NULL;
77 }
78
79 file_detail_ptr = (file_details *) malloc(sizeof(file_details) * num_file);
80 if (NULL == file_detail_ptr)
81 {
82 QLOGI("Fail to allocate memory");
83 remove_pkg(pkg_name);
84 free(pkg_name);
85 ATRACE_END();
86 return NULL;
87 }
88
89 num_of_files = get_file_list(pkg_name,file_detail_ptr,num_file);
90 QLOGI("num_of_files = %d",num_of_files);
91
92 if (num_of_files <= 0)
93 {
94 QLOGI("no file to read get_file_list");
95 remove_pkg(pkg_name);
96 free(file_detail_ptr);
97 free(pkg_name);
98 ATRACE_END();
99 return NULL;
100 }
101
102 if( num_file > MAX_NUM_FILE)
103 {
104 num_file = MAX_NUM_FILE;
105 }
106
107 for(i = 0; i < num_file;i++)
108 {
109 static unsigned int c_int = 0;
110 int fd = -1;
111 int num_pages = 0;
112 int page_ittr = 0;
113 char trace_buf[4096];
114 char *file_mmap = NULL;
115
116 snprintf(trace_buf,4096,"Opening file %s",file_detail_ptr[i].file_name);
117 ATRACE_BEGIN(trace_buf);
118 fd = open(file_detail_ptr[i].file_name, O_RDONLY);
119 if(fd == -1)
120 {
121 mark_for_delete(pkg_name,file_detail_ptr[i].file_name);
122 ATRACE_END();
123 continue;
124 }
125 if ( fstat( fd, &file_stat ) < 0 )
126 {
127 QLOGI("fail to get file stat");
128 mark_for_delete(pkg_name,file_detail_ptr[i].file_name);
129 close(fd);
130 ATRACE_END();
131 continue;// goto next file
132 }
133 if ( file_stat.st_size == 0 )
134 {
135 // File zie is zero
136 mark_for_delete(pkg_name,file_detail_ptr[i].file_name);
137 close(fd);
138 ATRACE_END();
139 continue;// goto next file
140 }
141 file_mmap = (char *)mmap(NULL, file_stat.st_size, PROT_READ
142 , MAP_SHARED| MAP_NORESERVE, fd, 0 );
143 if ( file_mmap == MAP_FAILED )
144 {
145 QLOGI("Fail to map the file");
146 mark_for_delete(pkg_name,file_detail_ptr[i].file_name);
147 close(fd);
148 ATRACE_END();
149 continue;// goto next file
150 }
151
152 snprintf(trace_buf,4096,"reading file %s size = %d",file_detail_ptr[i].file_name
153 ,(int)file_stat.st_size);
154 ATRACE_BEGIN(trace_buf);
155 num_pages = (file_stat.st_size + PAGE_SIZE - 1)/ PAGE_SIZE;
156 QLOGI("%d. mapping file %s pages = %d size = %d ",i,file_detail_ptr[i].file_name
157 ,num_pages,file_stat.st_size);
158 for(page_ittr = 0; page_ittr < num_pages ; page_ittr++)
159 {
160
161 c_int+= file_mmap[page_ittr*PAGE_SIZE];
162
163 total_data += PAGE_SIZE;
164 if(page_ittr*PAGE_SIZE > MAX_FILE_SIZE)
165 {
166 QLOGI("Max file size limit reached");
167 //Stop reading as reach on max file limit
168 break;
169 }
170 }
171
172 if (munmap(file_mmap, file_stat.st_size)) QLOGI("munmap failed");
173 ATRACE_END();
174 ATRACE_END();
175
176 close(fd);
177 if(total_data > MAX_TOTAL_DATA)
178 {
179 QLOGI("Max total size limit reached Total = %d",total_data);
180 //STOP reading and max total reached
181 break;
182 }
183 }
184
185
186 ATRACE_END();
187 QLOGI(" Total Data = %d",total_data);
188 free(pkg_name);
189 free(file_detail_ptr);
190 return NULL;
191}
那这块看源码就能知道，从数据库中查询到对应的文件，然后进行打开操作。那么问题来了。
是在什么地方文件的capture和playback呢？