icuSources/tools/toolutil/flagparser.cpp

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /******************************************************************************
   4  *   Copyright (C) 2009-2015, International Business Machines
   5  *   Corporation and others.  All Rights Reserved.
   6  *******************************************************************************
   7  */
   8
   9 #include "flagparser.h"
  10 #include "filestrm.h"
  11 #include "cstring.h"
  12 #include "cmemory.h"
  13
  14 #define DEFAULT_BUFFER_SIZE 512
  15
  16 static int32_t currentBufferSize = DEFAULT_BUFFER_SIZE;
  17
  18 static int32_t extractFlag(char* buffer, int32_t bufferSize, char* flag, int32_t flagSize, const char ** flagNames, int32_t numOfFlags, UErrorCode *status);
  19 static int32_t getFlagOffset(const char *buffer, int32_t bufferSize);
  20
  21 /*
  22  * Opens the given fileName and reads in the information storing the data in flagBuffer.
  23  */
  24 U_CAPI int32_t U_EXPORT2
  25 parseFlagsFile(const char *fileName, char **flagBuffer, int32_t flagBufferSize, const char ** flagNames, int32_t numOfFlags, UErrorCode *status) {
  26     char* buffer = NULL;
  27     char* tmpFlagBuffer = NULL;
  28     UBool allocateMoreSpace = FALSE;
  29     int32_t idx, i;
  30     int32_t result = 0;
  31
  32     FileStream *f = T_FileStream_open(fileName, "r");
  33     if (f == NULL) {
  34         *status = U_FILE_ACCESS_ERROR;
  35         goto parseFlagsFile_cleanup;
  36     }
  37
  38     buffer = (char *)uprv_malloc(sizeof(char) * currentBufferSize);
  39     tmpFlagBuffer = (char *)uprv_malloc(sizeof(char) * flagBufferSize);
  40
  41     if (buffer == NULL || tmpFlagBuffer == NULL) {
  42         *status = U_MEMORY_ALLOCATION_ERROR;
  43         goto parseFlagsFile_cleanup;
  44     }
  45
  46     do {
  47         if (allocateMoreSpace) {
  48             allocateMoreSpace = FALSE;
  49             currentBufferSize *= 2;
  50             uprv_free(buffer);
  51             buffer = (char *)uprv_malloc(sizeof(char) * currentBufferSize);
  52             if (buffer == NULL) {
  53                 *status = U_MEMORY_ALLOCATION_ERROR;
  54                 goto parseFlagsFile_cleanup;
  55             }
  56         }
  57         for (i = 0; i < numOfFlags;) {
  58             if (T_FileStream_readLine(f, buffer, currentBufferSize) == NULL) {
  59                 /* End of file reached. */
  60                 break;
  61             }
  62             if (buffer[0] == '#') {
  63                 continue;
  64             }
  65
  66             if ((int32_t)uprv_strlen(buffer) == (currentBufferSize - 1) && buffer[currentBufferSize-2] != '\n') {
  67                 /* Allocate more space for buffer if it didnot read the entrire line */
  68                 allocateMoreSpace = TRUE;
  69                 T_FileStream_rewind(f);
  70                 break;
  71             } else {
  72                 idx = extractFlag(buffer, currentBufferSize, tmpFlagBuffer, flagBufferSize, flagNames, numOfFlags, status);
  73                 if (U_FAILURE(*status)) {
  74                     if (*status == U_BUFFER_OVERFLOW_ERROR) {
  75                         result = currentBufferSize;
  76                     } else {
  77                         result = -1;
  78                     }
  79                     break;
  80                 } else {
  81                     if (flagNames != NULL) {
  82                         if (idx >= 0) {
  83                             uprv_strcpy(flagBuffer[idx], tmpFlagBuffer);
  84                         } else {
  85                             /* No match found.  Skip it. */
  86                             continue;
  87                         }
  88                     } else {
  89                         uprv_strcpy(flagBuffer[i++], tmpFlagBuffer);
  90                     }
  91                 }
  92             }
  93         }
  94     } while (allocateMoreSpace && U_SUCCESS(*status));
  95
  96 parseFlagsFile_cleanup:
  97     uprv_free(tmpFlagBuffer);
  98     uprv_free(buffer);
  99
 100     T_FileStream_close(f);
 101
 102     if (U_FAILURE(*status) && *status != U_BUFFER_OVERFLOW_ERROR) {
 103         return -1;
 104     }
 105
 106     if (U_SUCCESS(*status) && result == 0) {
 107         currentBufferSize = DEFAULT_BUFFER_SIZE;
 108     }
 109
 110     return result;
 111 }
 112
 113
 114 /*
 115  * Extract the setting after the '=' and store it in flag excluding the newline character.
 116  */
 117 static int32_t extractFlag(char* buffer, int32_t bufferSize, char* flag, int32_t flagSize, const char **flagNames, int32_t numOfFlags, UErrorCode *status) {
 118     int32_t i, idx = -1;
 119     char *pBuffer;
 120     int32_t offset=0;
 121     UBool bufferWritten = FALSE;
 122
 123     if (buffer[0] != 0) {
 124         /* Get the offset (i.e. position after the '=') */
 125         offset = getFlagOffset(buffer, bufferSize);
 126         pBuffer = buffer+offset;
 127         for(i = 0;;i++) {
 128             if (i >= flagSize) {
 129                 *status = U_BUFFER_OVERFLOW_ERROR;
 130                 return -1;
 131             }
 132             if (pBuffer[i+1] == 0) {
 133                 /* Indicates a new line character. End here. */
 134                 flag[i] = 0;
 135                 break;
 136             }
 137
 138             flag[i] = pBuffer[i];
 139             if (i == 0) {
 140                 bufferWritten = TRUE;
 141             }
 142         }
 143     }
 144
 145     if (!bufferWritten) {
 146         flag[0] = 0;
 147     }
 148
 149     if (flagNames != NULL && offset>0) {
 150         offset--;  /* Move offset back 1 because of '='*/
 151         for (i = 0; i < numOfFlags; i++) {
 152             if (uprv_strncmp(buffer, flagNames[i], offset) == 0) {
 153                 idx = i;
 154                 break;
 155             }
 156         }
 157     }
 158
 159     return idx;
 160 }
 161
 162 /*
 163  * Get the position after the '=' character.
 164  */
 165 static int32_t getFlagOffset(const char *buffer, int32_t bufferSize) {
 166     int32_t offset = 0;
 167
 168     for (offset = 0; offset < bufferSize;offset++) {
 169         if (buffer[offset] == '=') {
 170             offset++;
 171             break;
 172         }
 173     }
 174
 175     if (offset == bufferSize || (offset - 1) == bufferSize) {
 176         offset = 0;
 177     }
 178
 179     return offset;
 180 }