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      1 /*
      2  * Copyright (C) 2005 The Android Open Source Project
      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  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "misc"
     18 
     19 //
     20 // Miscellaneous utility functions.
     21 //
     22 #include <utils/misc.h>
     23 #include <utils/Log.h>
     24 
     25 #include <sys/stat.h>
     26 #include <string.h>
     27 #include <errno.h>
     28 #include <assert.h>
     29 #include <stdio.h>
     30 
     31 #if defined(HAVE_PTHREADS)
     32 # include <pthread.h>
     33 #endif
     34 
     35 #include <utils/Vector.h>
     36 
     37 using namespace android;
     38 
     39 namespace android {
     40 
     41 /*
     42  * Like strdup(), but uses C++ "new" operator instead of malloc.
     43  */
     44 char* strdupNew(const char* str)
     45 {
     46     char* newStr;
     47     int len;
     48 
     49     if (str == NULL)
     50         return NULL;
     51 
     52     len = strlen(str);
     53     newStr = new char[len+1];
     54     memcpy(newStr, str, len+1);
     55 
     56     return newStr;
     57 }
     58 
     59 /*
     60  * Concatenate an argument vector.
     61  */
     62 char* concatArgv(int argc, const char* const argv[])
     63 {
     64     char* newStr = NULL;
     65     int len, totalLen, posn, idx;
     66 
     67     /*
     68      * First, figure out the total length.
     69      */
     70     totalLen = idx = 0;
     71     while (1) {
     72         if (idx == argc || argv[idx] == NULL)
     73             break;
     74         if (idx)
     75             totalLen++;  // leave a space between args
     76         totalLen += strlen(argv[idx]);
     77         idx++;
     78     }
     79 
     80     /*
     81      * Alloc the string.
     82      */
     83     newStr = new char[totalLen +1];
     84     if (newStr == NULL)
     85         return NULL;
     86 
     87     /*
     88      * Finally, allocate the string and copy data over.
     89      */
     90     idx = posn = 0;
     91     while (1) {
     92         if (idx == argc || argv[idx] == NULL)
     93             break;
     94         if (idx)
     95             newStr[posn++] = ' ';
     96 
     97         len = strlen(argv[idx]);
     98         memcpy(&newStr[posn], argv[idx], len);
     99         posn += len;
    100 
    101         idx++;
    102     }
    103 
    104     assert(posn == totalLen);
    105     newStr[posn] = '\0';
    106 
    107     return newStr;
    108 }
    109 
    110 /*
    111  * Count the #of args in an argument vector.  Don't count the final NULL.
    112  */
    113 int countArgv(const char* const argv[])
    114 {
    115     int count = 0;
    116 
    117     while (argv[count] != NULL)
    118         count++;
    119 
    120     return count;
    121 }
    122 
    123 
    124 #include <stdio.h>
    125 /*
    126  * Get a file's type.
    127  */
    128 FileType getFileType(const char* fileName)
    129 {
    130     struct stat sb;
    131 
    132     if (stat(fileName, &sb) < 0) {
    133         if (errno == ENOENT || errno == ENOTDIR)
    134             return kFileTypeNonexistent;
    135         else {
    136             fprintf(stderr, "getFileType got errno=%d on '%s'\n",
    137                 errno, fileName);
    138             return kFileTypeUnknown;
    139         }
    140     } else {
    141         if (S_ISREG(sb.st_mode))
    142             return kFileTypeRegular;
    143         else if (S_ISDIR(sb.st_mode))
    144             return kFileTypeDirectory;
    145         else if (S_ISCHR(sb.st_mode))
    146             return kFileTypeCharDev;
    147         else if (S_ISBLK(sb.st_mode))
    148             return kFileTypeBlockDev;
    149         else if (S_ISFIFO(sb.st_mode))
    150             return kFileTypeFifo;
    151 #ifdef HAVE_SYMLINKS
    152         else if (S_ISLNK(sb.st_mode))
    153             return kFileTypeSymlink;
    154         else if (S_ISSOCK(sb.st_mode))
    155             return kFileTypeSocket;
    156 #endif
    157         else
    158             return kFileTypeUnknown;
    159     }
    160 }
    161 
    162 /*
    163  * Get a file's modification date.
    164  */
    165 time_t getFileModDate(const char* fileName)
    166 {
    167     struct stat sb;
    168 
    169     if (stat(fileName, &sb) < 0)
    170         return (time_t) -1;
    171 
    172     return sb.st_mtime;
    173 }
    174 
    175 /*
    176  * Round up to the next highest power of 2.
    177  *
    178  * Found on http://graphics.stanford.edu/~seander/bithacks.html.
    179  */
    180 unsigned int roundUpPower2(unsigned int val)
    181 {
    182     val--;
    183     val |= val >> 1;
    184     val |= val >> 2;
    185     val |= val >> 4;
    186     val |= val >> 8;
    187     val |= val >> 16;
    188     val++;
    189 
    190     return val;
    191 }
    192 
    193 struct sysprop_change_callback_info {
    194     sysprop_change_callback callback;
    195     int priority;
    196 };
    197 
    198 #if defined(HAVE_PTHREADS)
    199 static pthread_mutex_t gSyspropMutex = PTHREAD_MUTEX_INITIALIZER;
    200 static Vector<sysprop_change_callback_info>* gSyspropList = NULL;
    201 #endif
    202 
    203 void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
    204 #if defined(HAVE_PTHREADS)
    205     pthread_mutex_lock(&gSyspropMutex);
    206     if (gSyspropList == NULL) {
    207         gSyspropList = new Vector<sysprop_change_callback_info>();
    208     }
    209     sysprop_change_callback_info info;
    210     info.callback = cb;
    211     info.priority = priority;
    212     bool added = false;
    213     for (size_t i=0; i<gSyspropList->size(); i++) {
    214         if (priority >= gSyspropList->itemAt(i).priority) {
    215             gSyspropList->insertAt(info, i);
    216             added = true;
    217             break;
    218         }
    219     }
    220     if (!added) {
    221         gSyspropList->add(info);
    222     }
    223     pthread_mutex_unlock(&gSyspropMutex);
    224 #endif
    225 }
    226 
    227 void report_sysprop_change() {
    228 #if defined(HAVE_PTHREADS)
    229     pthread_mutex_lock(&gSyspropMutex);
    230     Vector<sysprop_change_callback_info> listeners;
    231     if (gSyspropList != NULL) {
    232         listeners = *gSyspropList;
    233     }
    234     pthread_mutex_unlock(&gSyspropMutex);
    235 
    236     //ALOGI("Reporting sysprop change to %d listeners", listeners.size());
    237     for (size_t i=0; i<listeners.size(); i++) {
    238         listeners[i].callback();
    239     }
    240 #endif
    241 }
    242 
    243 }; // namespace android
    244