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Arduino/hardware/arduino/avr/libraries/Robot_Control/Fat16.cpp
Cristian Maglie 3394f61276 Merged 1.0.5
2013-05-29 18:30:36 +02:00

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/* Arduino FAT16 Library
* Copyright (C) 2008 by William Greiman
*
* This file is part of the Arduino FAT16 Library
*
* This Library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This Library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with the Arduino Fat16 Library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <avr/pgmspace.h>
#if ARDUINO < 100
#include <WProgram.h>
#else // ARDUINO
#include <Arduino.h>
#endif // ARDUINO
#include <Fat16.h>
//-----------------------------------------------------------------------------
// volume info
uint8_t Fat16::volumeInitialized_ = 0; // true if FAT16 volume is valid
uint8_t Fat16::fatCount_; // number of file allocation tables
uint8_t Fat16::blocksPerCluster_; // must be power of 2
uint16_t Fat16::rootDirEntryCount_; // should be 512 for FAT16
fat_t Fat16::blocksPerFat_; // number of blocks in one FAT
fat_t Fat16::clusterCount_; // total clusters in volume
uint32_t Fat16::fatStartBlock_; // start of first FAT
uint32_t Fat16::rootDirStartBlock_; // start of root dir
uint32_t Fat16::dataStartBlock_; // start of data clusters
//------------------------------------------------------------------------------
// raw block cache
SdCard *Fat16::rawDev_ = 0; // class for block read and write
uint32_t Fat16::cacheBlockNumber_ = 0XFFFFFFFF; // init to invalid block number
cache16_t Fat16::cacheBuffer_; // 512 byte cache for SdCard
uint8_t Fat16::cacheDirty_ = 0; // cacheFlush() will write block if true
uint32_t Fat16::cacheMirrorBlock_ = 0; // mirror block for second FAT
//------------------------------------------------------------------------------
// callback function for date/time
void (*Fat16::dateTime_)(uint16_t* date, uint16_t* time) = NULL;
#if ALLOW_DEPRECATED_FUNCTIONS
void (*Fat16::oldDateTime_)(uint16_t& date, uint16_t& time) = NULL; // NOLINT
#endif // ALLOW_DEPRECATED_FUNCTIONS
//------------------------------------------------------------------------------
// format 8.3 name for directory entry
static uint8_t make83Name(const char* str, uint8_t* name) {
uint8_t c;
uint8_t n = 7; // max index for part before dot
uint8_t i = 0;
// blank fill name and extension
while (i < 11) name[i++] = ' ';
i = 0;
while ((c = *str++) != '\0') {
if (c == '.') {
if (n == 10) return false; // only one dot allowed
n = 10; // max index for full 8.3 name
i = 8; // place for extension
} else {
// illegal FAT characters
PGM_P p = PSTR("|<>^+=?/[];,*\"\\");
uint8_t b;
while ((b = pgm_read_byte(p++))) if (b == c) return false;
// check length and only allow ASCII printable characters
if (i > n || c < 0X21 || c > 0X7E) return false;
// only upper case allowed in 8.3 names - convert lower to upper
name[i++] = c < 'a' || c > 'z' ? c : c + ('A' - 'a');
}
}
// must have a file name, extension is optional
return name[0] != ' ';
}
//==============================================================================
// Fat16 member functions
//------------------------------------------------------------------------------
uint8_t Fat16::addCluster(void) {
// start search after last cluster of file or at cluster two in FAT
fat_t freeCluster = curCluster_ ? curCluster_ : 1;
for (fat_t i = 0; ; i++) {
// return no free clusters
if (i >= clusterCount_) return false;
// Fat has clusterCount + 2 entries
if (freeCluster > clusterCount_) freeCluster = 1;
freeCluster++;
fat_t value;
if (!fatGet(freeCluster, &value)) return false;
if (value == 0) break;
}
// mark cluster allocated
if (!fatPut(freeCluster, FAT16EOC)) return false;
if (curCluster_ != 0) {
// link cluster to chain
if (!fatPut(curCluster_, freeCluster)) return false;
} else {
// first cluster of file so update directory entry
flags_ |= F_FILE_DIR_DIRTY;
firstCluster_ = freeCluster;
}
curCluster_ = freeCluster;
return true;
}
//------------------------------------------------------------------------------
//
dir_t* Fat16::cacheDirEntry(uint16_t index, uint8_t action) {
if (index >= rootDirEntryCount_) return NULL;
if (!cacheRawBlock(rootDirStartBlock_ + (index >> 4), action)) return NULL;
return &cacheBuffer_.dir[index & 0XF];
}
//------------------------------------------------------------------------------
//
uint8_t Fat16::cacheFlush(void) {
if (cacheDirty_) {
if (!rawDev_->writeBlock(cacheBlockNumber_, cacheBuffer_.data)) {
return false;
}
// mirror FAT tables
if (cacheMirrorBlock_) {
if (!rawDev_->writeBlock(cacheMirrorBlock_, cacheBuffer_.data)) {
return false;
}
cacheMirrorBlock_ = 0;
}
cacheDirty_ = 0;
}
return true;
}
//------------------------------------------------------------------------------
//
uint8_t Fat16::cacheRawBlock(uint32_t blockNumber, uint8_t action) {
if (cacheBlockNumber_ != blockNumber) {
if (!cacheFlush()) return false;
if (!rawDev_->readBlock(blockNumber, cacheBuffer_.data)) return false;
cacheBlockNumber_ = blockNumber;
}
cacheDirty_ |= action;
return true;
}
//------------------------------------------------------------------------------
/**
* Close a file and force cached data and directory information
* to be written to the storage device.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include no file is open or an I/O error.
*/
uint8_t Fat16::close(void) {
if (!sync()) return false;
flags_ = 0;
return true;
}
//------------------------------------------------------------------------------
/**
* Return a files directory entry
*
* \param[out] dir Location for return of the files directory entry.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*/
uint8_t Fat16::dirEntry(dir_t* dir) {
if (!sync()) return false;
dir_t* p = cacheDirEntry(dirEntryIndex_, CACHE_FOR_WRITE);
if (!p) return false;
memcpy(dir, p, sizeof(dir_t));
return true;
}
//------------------------------------------------------------------------------
uint8_t Fat16::fatGet(fat_t cluster, fat_t* value) {
if (cluster > (clusterCount_ + 1)) return false;
uint32_t lba = fatStartBlock_ + (cluster >> 8);
if (lba != cacheBlockNumber_) {
if (!cacheRawBlock(lba)) return false;
}
*value = cacheBuffer_.fat[cluster & 0XFF];
return true;
}
//------------------------------------------------------------------------------
uint8_t Fat16::fatPut(fat_t cluster, fat_t value) {
if (cluster < 2) return false;
if (cluster > (clusterCount_ + 1)) return false;
uint32_t lba = fatStartBlock_ + (cluster >> 8);
if (lba != cacheBlockNumber_) {
if (!cacheRawBlock(lba)) return false;
}
cacheBuffer_.fat[cluster & 0XFF] = value;
cacheSetDirty();
// mirror second FAT
if (fatCount_ > 1) cacheMirrorBlock_ = lba + blocksPerFat_;
return true;
}
//------------------------------------------------------------------------------
// free a cluster chain
uint8_t Fat16::freeChain(fat_t cluster) {
while (1) {
fat_t next;
if (!fatGet(cluster, &next)) return false;
if (!fatPut(cluster, 0)) return false;
if (isEOC(next)) return true;
cluster = next;
}
}
//------------------------------------------------------------------------------
/**
* Initialize a FAT16 volume.
*
* \param[in] dev The SdCard where the volume is located.
*
* \param[in] part The partition to be used. Legal values for \a part are
* 1-4 to use the corresponding partition on a device formatted with
* a MBR, Master Boot Record, or zero if the device is formatted as
* a super floppy with the FAT boot sector in block zero.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure. reasons for
* failure include not finding a valid FAT16 file system in the
* specified partition, a call to init() after a volume has
* been successful initialized or an I/O error.
*
*/
uint8_t Fat16::init(SdCard* dev, uint8_t part) {
// error if invalid partition
if (part > 4) return false;
rawDev_ = dev;
uint32_t volumeStartBlock = 0;
// if part == 0 assume super floppy with FAT16 boot sector in block zero
// if part > 0 assume mbr volume with partition table
if (part) {
if (!cacheRawBlock(volumeStartBlock)) return false;
volumeStartBlock = cacheBuffer_.mbr.part[part - 1].firstSector;
}
if (!cacheRawBlock(volumeStartBlock)) return false;
// check boot block signature
if (cacheBuffer_.data[510] != BOOTSIG0 ||
cacheBuffer_.data[511] != BOOTSIG1) return false;
bpb_t* bpb = &cacheBuffer_.fbs.bpb;
fatCount_ = bpb->fatCount;
blocksPerCluster_ = bpb->sectorsPerCluster;
blocksPerFat_ = bpb->sectorsPerFat16;
rootDirEntryCount_ = bpb->rootDirEntryCount;
fatStartBlock_ = volumeStartBlock + bpb->reservedSectorCount;
rootDirStartBlock_ = fatStartBlock_ + bpb->fatCount*bpb->sectorsPerFat16;
dataStartBlock_ = rootDirStartBlock_
+ ((32*bpb->rootDirEntryCount + 511)/512);
uint32_t totalBlocks = bpb->totalSectors16 ?
bpb->totalSectors16 : bpb->totalSectors32;
clusterCount_ = (totalBlocks - (dataStartBlock_ - volumeStartBlock))
/bpb->sectorsPerCluster;
// verify valid FAT16 volume
if (bpb->bytesPerSector != 512 // only allow 512 byte blocks
|| bpb->sectorsPerFat16 == 0 // zero for FAT32
|| clusterCount_ < 4085 // FAT12 if true
|| totalBlocks > 0X800000 // Max size for FAT16 volume
|| bpb->reservedSectorCount == 0 // invalid volume
|| bpb->fatCount == 0 // invalid volume
|| bpb->sectorsPerFat16 < (clusterCount_ >> 8) // invalid volume
|| bpb->sectorsPerCluster == 0 // invalid volume
// power of 2 test
|| bpb->sectorsPerCluster & (bpb->sectorsPerCluster - 1)) {
// not a usable FAT16 bpb
return false;
}
volumeInitialized_ = 1;
return true;
}
//------------------------------------------------------------------------------
/** List directory contents to Serial.
*
* \param[in] flags The inclusive OR of
*
* LS_DATE - %Print file modification date
*
* LS_SIZE - %Print file size.
*/
void Fat16::ls(uint8_t flags) {
dir_t d;
for (uint16_t index = 0; readDir(&d, &index, DIR_ATT_VOLUME_ID); index++) {
// print file name with possible blank fill
printDirName(d, flags & (LS_DATE | LS_SIZE) ? 14 : 0);
// print modify date/time if requested
if (flags & LS_DATE) {
printFatDate(d.lastWriteDate);
Serial.write(' ');
printFatTime(d.lastWriteTime);
}
// print size if requested
if (DIR_IS_FILE(&d) && (flags & LS_SIZE)) {
Serial.write(' ');
Serial.print(d.fileSize);
}
Serial.println();
}
}
//------------------------------------------------------------------------------
/**
* Open a file by file name.
*
* \note The file must be in the root directory and must have a DOS
* 8.3 name.
*
* \param[in] fileName A valid 8.3 DOS name for a file in the root directory.
*
* \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
* OR of flags from the following list
*
* O_READ - Open for reading.
*
* O_RDONLY - Same as O_READ.
*
* O_WRITE - Open for writing.
*
* O_WRONLY - Same as O_WRITE.
*
* O_RDWR - Open for reading and writing.
*
* O_APPEND - If set, the file offset shall be set to the end of the
* file prior to each write.
*
* O_CREAT - If the file exists, this flag has no effect except as noted
* under O_EXCL below. Otherwise, the file shall be created
*
* O_EXCL - If O_CREAT and O_EXCL are set, open() shall fail if the file exists.
*
* O_SYNC - Call sync() after each write. This flag should not be used with
* write(uint8_t), write_P(PGM_P), writeln_P(PGM_P), or the Arduino Print class.
* These functions do character a time writes so sync() will be called
* after each byte.
*
* O_TRUNC - If the file exists and is a regular file, and the file is
* successfully opened and is not read only, its length shall be truncated to 0.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include the FAT volume has not been initialized,
* a file is already open, \a fileName is invalid, the file does not exist,
* is a directory, or can't be opened in the access mode specified by oflag.
*/
uint8_t Fat16::open(const char* fileName, uint8_t oflag) {
uint8_t dname[11]; // name formated for dir entry
int16_t empty = -1; // index of empty slot
dir_t* p; // pointer to cached dir entry
if (!volumeInitialized_ || isOpen()) return false;
// error if invalid name
if (!make83Name(fileName, dname)) return false;
for (uint16_t index = 0; index < rootDirEntryCount_; index++) {
if (!(p = cacheDirEntry(index))) return false;
if (p->name[0] == DIR_NAME_FREE || p->name[0] == DIR_NAME_DELETED) {
// remember first empty slot
if (empty < 0) empty = index;
// done if no entries follow
if (p->name[0] == DIR_NAME_FREE) break;
} else if (!memcmp(dname, p->name, 11)) {
// don't open existing file if O_CREAT and O_EXCL
if ((oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) return false;
// open existing file
return open(index, oflag);
}
}
// error if directory is full
if (empty < 0) return false;
// only create file if O_CREAT and O_WRITE
if ((oflag & (O_CREAT | O_WRITE)) != (O_CREAT | O_WRITE)) return false;
if (!(p = cacheDirEntry(empty, CACHE_FOR_WRITE))) return false;
// initialize as empty file
memset(p, 0, sizeof(dir_t));
memcpy(p->name, dname, 11);
// set timestamps
if (dateTime_) {
// call user function
dateTime_(&p->creationDate, &p->creationTime);
} else {
// use default date/time
p->creationDate = FAT_DEFAULT_DATE;
p->creationTime = FAT_DEFAULT_TIME;
}
p->lastAccessDate = p->creationDate;
p->lastWriteDate = p->creationDate;
p->lastWriteTime = p->creationTime;
// insure created directory entry will be written to storage device
if (!cacheFlush()) return false;
// open entry
return open(empty, oflag);
}
//------------------------------------------------------------------------------
/**
* Open a file by file index.
*
* \param[in] index The root directory index of the file to be opened. See \link
* Fat16::readDir() readDir()\endlink.
*
* \param[in] oflag See \link Fat16::open(const char*, uint8_t)\endlink.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include the FAT volume has not been initialized,
* a file is already open, \a index is invalid or is not the index of a
* file or the file cannot be opened in the access mode specified by oflag.
*/
uint8_t Fat16::open(uint16_t index, uint8_t oflag) {
if (!volumeInitialized_ || isOpen()) return false;
if ((oflag & O_TRUNC) && !(oflag & O_WRITE)) return false;
dir_t* d = cacheDirEntry(index);
// if bad file index or I/O error
if (!d) return false;
// error if unused entry
if (d->name[0] == DIR_NAME_FREE || d->name[0] == DIR_NAME_DELETED) {
return false;
}
// error if long name, volume label or subdirectory
if ((d->attributes & (DIR_ATT_VOLUME_ID | DIR_ATT_DIRECTORY)) != 0) {
return false;
}
// don't allow write or truncate if read-only
if (d->attributes & DIR_ATT_READ_ONLY) {
if (oflag & (O_WRITE | O_TRUNC)) return false;
}
curCluster_ = 0;
curPosition_ = 0;
dirEntryIndex_ = index;
fileSize_ = d->fileSize;
firstCluster_ = d->firstClusterLow;
flags_ = oflag & (O_ACCMODE | O_SYNC | O_APPEND);
if (oflag & O_TRUNC ) return truncate(0);
return true;
}
//------------------------------------------------------------------------------
/** %Print the name field of a directory entry in 8.3 format to Serial.
*
* \param[in] dir The directory structure containing the name.
* \param[in] width Blank fill name if length is less than \a width.
*/
void Fat16::printDirName(const dir_t& dir, uint8_t width) {
uint8_t w = 0;
for (uint8_t i = 0; i < 11; i++) {
if (dir.name[i] == ' ') continue;
if (i == 8) {
Serial.write('.');
w++;
}
Serial.write(dir.name[i]);
w++;
}
if (DIR_IS_SUBDIR(&dir)) {
Serial.write('/');
w++;
}
while (w < width) {
Serial.write(' ');
w++;
}
}
//------------------------------------------------------------------------------
/** %Print a directory date field to Serial.
*
* Format is yyyy-mm-dd.
*
* \param[in] fatDate The date field from a directory entry.
*/
void Fat16::printFatDate(uint16_t fatDate) {
Serial.print(FAT_YEAR(fatDate));
Serial.write('-');
printTwoDigits(FAT_MONTH(fatDate));
Serial.write('-');
printTwoDigits(FAT_DAY(fatDate));
}
//------------------------------------------------------------------------------
/** %Print a directory time field to Serial.
*
* Format is hh:mm:ss.
*
* \param[in] fatTime The time field from a directory entry.
*/
void Fat16::printFatTime(uint16_t fatTime) {
printTwoDigits(FAT_HOUR(fatTime));
Serial.write(':');
printTwoDigits(FAT_MINUTE(fatTime));
Serial.write(':');
printTwoDigits(FAT_SECOND(fatTime));
}
//------------------------------------------------------------------------------
/** %Print a value as two digits to Serial.
*
* \param[in] v Value to be printed, 0 <= \a v <= 99
*/
void Fat16::printTwoDigits(uint8_t v) {
char str[3];
str[0] = '0' + v/10;
str[1] = '0' + v % 10;
str[2] = 0;
Serial.print(str);
}
//------------------------------------------------------------------------------
/**
* Read the next byte from a file.
*
* \return For success read returns the next byte in the file as an int.
* If an error occurs or end of file is reached -1 is returned.
*/
int16_t Fat16::read(void) {
uint8_t b;
return read(&b, 1) == 1 ? b : -1;
}
//------------------------------------------------------------------------------
/**
* Read data from a file at starting at the current file position.
*
* \param[out] buf Pointer to the location that will receive the data.
*
* \param[in] nbyte Maximum number of bytes to read.
*
* \return For success read returns the number of bytes read.
* A value less than \a nbyte, including zero, may be returned
* if end of file is reached.
* If an error occurs, read returns -1. Possible errors include
* read called before a file has been opened, the file has not been opened in
* read mode, a corrupt file system, or an I/O error.
*/
int16_t Fat16::read(void* buf, uint16_t nbyte) {
// convert void pointer to uin8_t pointer
uint8_t* dst = reinterpret_cast<uint8_t*>(buf);
// error if not open for read
if (!(flags_ & O_READ)) return -1;
// don't read beyond end of file
if ((curPosition_ + nbyte) > fileSize_) nbyte = fileSize_ - curPosition_;
// bytes left to read in loop
uint16_t nToRead = nbyte;
while (nToRead > 0) {
uint8_t blkOfCluster = blockOfCluster(curPosition_);
uint16_t blockOffset = cacheDataOffset(curPosition_);
if (blkOfCluster == 0 && blockOffset == 0) {
// start next cluster
if (curCluster_ == 0) {
curCluster_ = firstCluster_;
} else {
if (!fatGet(curCluster_, &curCluster_)) return -1;
}
// return error if bad cluster chain
if (curCluster_ < 2 || isEOC(curCluster_)) return -1;
}
// cache data block
if (!cacheRawBlock(dataBlockLba(curCluster_, blkOfCluster))) return -1;
// location of data in cache
uint8_t* src = cacheBuffer_.data + blockOffset;
// max number of byte available in block
uint16_t n = 512 - blockOffset;
// lesser of available and amount to read
if (n > nToRead) n = nToRead;
// copy data to caller
memcpy(dst, src, n);
curPosition_ += n;
dst += n;
nToRead -= n;
}
return nbyte;
}
//------------------------------------------------------------------------------
/**
* Read the next short, 8.3, directory entry.
*
* Unused entries and entries for long names are skipped.
*
* \param[out] dir Location that will receive the entry.
*
* \param[in,out] index The search starts at \a index and \a index is
* updated with the root directory index of the found directory entry.
* If the entry is a file, it may be opened by calling
* \link Fat16::open(uint16_t, uint8_t) \endlink.
*
* \param[in] skip Skip entries that have these attributes. If \a skip
* is not specified, the default is to skip the volume label and directories.
*
* \return The value one, true, is returned for success and the value zero,
* false, is returned if an error occurs or the end of the root directory is
* reached. On success, \a entry is set to the index of the found directory
* entry.
*/
uint8_t Fat16::readDir(dir_t* dir, uint16_t* index, uint8_t skip) {
dir_t* p;
for (uint16_t i = *index; ; i++) {
if (i >= rootDirEntryCount_) return false;
if (!(p = cacheDirEntry(i))) return false;
// done if beyond last used entry
if (p->name[0] == DIR_NAME_FREE) return false;
// skip deleted entry
if (p->name[0] == DIR_NAME_DELETED) continue;
// skip long names
if ((p->attributes & DIR_ATT_LONG_NAME_MASK) == DIR_ATT_LONG_NAME) continue;
// skip if attribute match
if (p->attributes & skip) continue;
// return found index
*index = i;
break;
}
memcpy(dir, p, sizeof(dir_t));
return true;
}
//------------------------------------------------------------------------------
/**
* Remove a file. The directory entry and all data for the file are deleted.
*
* \note This function should not be used to delete the 8.3 version of a
* file that has a long name. For example if a file has the long name
* "New Text Document.txt" you should not delete the 8.3 name "NEWTEX~1.TXT".
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include the file is not open for write
* or an I/O error occurred.
*/
uint8_t Fat16::remove(void) {
// error if file is not open for write
if (!(flags_ & O_WRITE)) return false;
if (firstCluster_) {
if (!freeChain(firstCluster_)) return false;
}
dir_t* d = cacheDirEntry(dirEntryIndex_, CACHE_FOR_WRITE);
if (!d) return false;
d->name[0] = DIR_NAME_DELETED;
flags_ = 0;
return cacheFlush();
}
//------------------------------------------------------------------------------
/**
* Remove a file.
*
* The directory entry and all data for the file are deleted.
*
* \param[in] fileName The name of the file to be removed.
*
* \note This function should not be used to delete the 8.3 version of a
* file that has a long name. For example if a file has the long name
* "New Text Document.txt" you should not delete the 8.3 name "NEWTEX~1.TXT".
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include the file is read only, \a fileName is not found
* or an I/O error occurred.
*/
uint8_t Fat16::remove(const char* fileName) {
Fat16 file;
if (!file.open(fileName, O_WRITE)) return false;
return file.remove();
}
//------------------------------------------------------------------------------
/**
* Sets the file's read/write position.
*
* \param[in] pos The new position in bytes from the beginning of the file.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*/
uint8_t Fat16::seekSet(uint32_t pos) {
// error if file not open or seek past end of file
if (!isOpen() || pos > fileSize_) return false;
if (pos == 0) {
// set position to start of file
curCluster_ = 0;
curPosition_ = 0;
return true;
}
fat_t n = ((pos - 1) >> 9)/blocksPerCluster_;
if (pos < curPosition_ || curPosition_ == 0) {
// must follow chain from first cluster
curCluster_ = firstCluster_;
} else {
// advance from curPosition
n -= ((curPosition_ - 1) >> 9)/blocksPerCluster_;
}
while (n--) {
if (!fatGet(curCluster_, &curCluster_)) return false;
}
curPosition_ = pos;
return true;
}
//------------------------------------------------------------------------------
/**
* The sync() call causes all modified data and directory fields
* to be written to the storage device.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include a call to sync() before a file has been
* opened or an I/O error.
*/
uint8_t Fat16::sync(void) {
if (flags_ & F_FILE_DIR_DIRTY) {
// cache directory entry
dir_t* d = cacheDirEntry(dirEntryIndex_, CACHE_FOR_WRITE);
if (!d) return false;
// update file size and first cluster
d->fileSize = fileSize_;
d->firstClusterLow = firstCluster_;
// set modify time if user supplied a callback date/time function
if (dateTime_) {
dateTime_(&d->lastWriteDate, &d->lastWriteTime);
d->lastAccessDate = d->lastWriteDate;
}
flags_ &= ~F_FILE_DIR_DIRTY;
}
return cacheFlush();
}
//------------------------------------------------------------------------------
/**
* The timestamp() call sets a file's timestamps in its directory entry.
*
* \param[in] flags Values for \a flags are constructed by a bitwise-inclusive
* OR of flags from the following list
*
* T_ACCESS - Set the file's last access date.
*
* T_CREATE - Set the file's creation date and time.
*
* T_WRITE - Set the file's last write/modification date and time.
*
* \param[in] year Valid range 1980 - 2107 inclusive.
*
* \param[in] month Valid range 1 - 12 inclusive.
*
* \param[in] day Valid range 1 - 31 inclusive.
*
* \param[in] hour Valid range 0 - 23 inclusive.
*
* \param[in] minute Valid range 0 - 59 inclusive.
*
* \param[in] second Valid range 0 - 59 inclusive
*
* \note It is possible to set an invalid date since there is no check for
* the number of days in a month.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*/
uint8_t Fat16::timestamp(uint8_t flags, uint16_t year, uint8_t month,
uint8_t day, uint8_t hour, uint8_t minute, uint8_t second) {
if (!isOpen()
|| year < 1980
|| year > 2107
|| month < 1
|| month > 12
|| day < 1
|| day > 31
|| hour > 23
|| minute > 59
|| second > 59) {
return false;
}
dir_t* d = cacheDirEntry(dirEntryIndex_, CACHE_FOR_WRITE);
if (!d) return false;
uint16_t dirDate = FAT_DATE(year, month, day);
uint16_t dirTime = FAT_TIME(hour, minute, second);
if (flags & T_ACCESS) {
d->lastAccessDate = dirDate;
}
if (flags & T_CREATE) {
d->creationDate = dirDate;
d->creationTime = dirTime;
// seems to be units of 1/100 second not 1/10 as Microsoft standard states
d->creationTimeTenths = second & 1 ? 100 : 0;
}
if (flags & T_WRITE) {
d->lastWriteDate = dirDate;
d->lastWriteTime = dirTime;
}
cacheSetDirty();
return sync();
}
//------------------------------------------------------------------------------
/**
* Truncate a file to a specified length. The current file position
* will be maintained if it is less than or equal to \a length otherwise
* it will be set to end of file.
*
* \param[in] length The desired length for the file.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
* Reasons for failure include file is read only, file is a directory,
* \a length is greater than the current file size or an I/O error occurs.
*/
uint8_t Fat16::truncate(uint32_t length) {
// error if file is not open for write
if (!(flags_ & O_WRITE)) return false;
if (length > fileSize_) return false;
// fileSize and length are zero - nothing to do
if (fileSize_ == 0) return true;
uint32_t newPos = curPosition_ > length ? length : curPosition_;
if (length == 0) {
// free all clusters
if (!freeChain(firstCluster_)) return false;
curCluster_ = firstCluster_ = 0;
} else {
fat_t toFree;
if (!seekSet(length)) return false;
if (!fatGet(curCluster_, &toFree)) return false;
if (!isEOC(toFree)) {
// free extra clusters
if (!fatPut(curCluster_, FAT16EOC)) return false;
if (!freeChain(toFree)) return false;
}
}
fileSize_ = length;
flags_ |= F_FILE_DIR_DIRTY;
if (!sync()) return false;
return seekSet(newPos);
}
//------------------------------------------------------------------------------
/**
* Write data at the current position of an open file.
*
* \note Data is moved to the cache but may not be written to the
* storage device until sync() is called.
*
* \param[in] buf Pointer to the location of the data to be written.
*
* \param[in] nbyte Number of bytes to write.
*
* \return For success write() returns the number of bytes written, always
* \a nbyte. If an error occurs, write() returns -1. Possible errors include
* write() is called before a file has been opened, the file has not been opened
* for write, device is full, a corrupt file system or an I/O error.
*
*/
int16_t Fat16::write(const void* buf, uint16_t nbyte) {
uint16_t nToWrite = nbyte;
const uint8_t* src = reinterpret_cast<const uint8_t*>(buf);
// error if file is not open for write
if (!(flags_ & O_WRITE)) goto writeErrorReturn;
// go to end of file if O_APPEND
if ((flags_ & O_APPEND) && curPosition_ != fileSize_) {
if (!seekEnd()) goto writeErrorReturn;
}
while (nToWrite > 0) {
uint8_t blkOfCluster = blockOfCluster(curPosition_);
uint16_t blockOffset = cacheDataOffset(curPosition_);
if (blkOfCluster == 0 && blockOffset == 0) {
// start of new cluster
if (curCluster_ == 0) {
if (firstCluster_ == 0) {
// allocate first cluster of file
if (!addCluster()) goto writeErrorReturn;
} else {
curCluster_ = firstCluster_;
}
} else {
fat_t next;
if (!fatGet(curCluster_, &next)) goto writeErrorReturn;
if (isEOC(next)) {
// add cluster if at end of chain
if (!addCluster()) goto writeErrorReturn;
} else {
curCluster_ = next;
}
}
}
uint32_t lba = dataBlockLba(curCluster_, blkOfCluster);
if (blockOffset == 0 && curPosition_ >= fileSize_) {
// start of new block don't need to read into cache
if (!cacheFlush()) goto writeErrorReturn;
cacheBlockNumber_ = lba;
cacheSetDirty();
} else {
// rewrite part of block
if (!cacheRawBlock(lba, CACHE_FOR_WRITE)) return -1;
}
uint8_t* dst = cacheBuffer_.data + blockOffset;
// max space in block
uint16_t n = 512 - blockOffset;
// lesser of space and amount to write
if (n > nToWrite) n = nToWrite;
// copy data to cache
memcpy(dst, src, n);
curPosition_ += n;
nToWrite -= n;
src += n;
}
if (curPosition_ > fileSize_) {
// update fileSize and insure sync will update dir entry
fileSize_ = curPosition_;
flags_ |= F_FILE_DIR_DIRTY;
} else if (dateTime_ && nbyte) {
// insure sync will update modified date and time
flags_ |= F_FILE_DIR_DIRTY;
}
if (flags_ & O_SYNC) {
if (!sync()) goto writeErrorReturn;
}
return nbyte;
writeErrorReturn:
writeError = true;
return -1;
}
//------------------------------------------------------------------------------
/**
* Write a byte to a file. Required by the Arduino Print class.
*
* Use Fat16::writeError to check for errors.
*/
#if ARDUINO < 100
void Fat16::write(uint8_t b) {
write(&b, 1);
}
#else // ARDUINO < 100
size_t Fat16::write(uint8_t b) {
return write(&b, 1) == 1 ? 1 : 0;
}
#endif // ARDUINO < 100
//------------------------------------------------------------------------------
/**
* Write a string to a file. Used by the Arduino Print class.
*
* Use Fat16::writeError to check for errors.
*/
#if ARDUINO < 100
void Fat16::write(const char* str) {
write(str, strlen(str));
}
#else // ARDUINO < 100
int16_t Fat16::write(const char* str) {
return write(str, strlen(str));
}
#endif // ARDUINO < 100
//------------------------------------------------------------------------------
/**
* Write a PROGMEM string to a file.
*
* Use Fat16::writeError to check for errors.
*/
void Fat16::write_P(PGM_P str) {
for (uint8_t c; (c = pgm_read_byte(str)); str++) write(c);
}
//------------------------------------------------------------------------------
/**
* Write a PROGMEM string followed by CR/LF to a file.
*
* Use Fat16::writeError to check for errors.
*/
void Fat16::writeln_P(PGM_P str) {
write_P(str);
println();
}
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