// This function determines the number of whole or partial log files in the DataFlash
// Wholly overwritten files are (of course) lost.
uint16_t DataFlash_Block::get_num_logs(void)
{
uint16_t lastpage;
uint16_t last;
uint16_t first;
if (find_last_page() == 1) {
return 0;
}
StartRead(1);
if (GetFileNumber() == 0xFFFF) {
return 0;
}
lastpage = find_last_page();
StartRead(lastpage);
last = GetFileNumber();
StartRead(lastpage + 2);
first = GetFileNumber();
if(first > last) {
StartRead(1);
first = GetFileNumber();
}
if (last == first) {
return 1;
}
return (last - first + 1);
}
// This function finds the last page of a particular log file
uint16_t DataFlash_Block::find_last_page_of_log(uint16_t log_number)
{
uint16_t look;
uint16_t bottom;
uint16_t top;
uint32_t look_hash;
uint32_t check_hash;
if(check_wrapped())
{
StartRead(1);
bottom = GetFileNumber();
if (bottom > log_number)
{
bottom = find_last_page();
top = df_NumPages;
} else {
bottom = 1;
top = find_last_page();
}
} else {
bottom = 1;
top = find_last_page();
}
check_hash = (int32_t)log_number<<16 | 0xFFFF;
while(top-bottom > 1)
{
look = (top+bottom)/2;
StartRead(look);
look_hash = (int32_t)GetFileNumber()<<16 | GetFilePage();
if (look_hash >= 0xFFFF0000) look_hash = 0;
if(look_hash > check_hash) {
// move down
top = look;
} else {
// move up
bottom = look;
}
}
StartRead(top);
if (GetFileNumber() == log_number) return top;
StartRead(bottom);
if (GetFileNumber() == log_number) return bottom;
return -1;
}
// This function finds the first and last pages of a log file
// The first page may be greater than the last page if the DataFlash has been filled and partially overwritten.
void DataFlash_Block::get_log_boundaries(uint16_t log_num, uint16_t & start_page, uint16_t & end_page)
{
uint16_t num = get_num_logs();
uint16_t look;
if (df_BufferIdx != 0) {
FinishWrite();
hal.scheduler->delay(100);
}
if(num == 1)
{
StartRead(df_NumPages);
if (GetFileNumber() == 0xFFFF)
{
start_page = 1;
end_page = find_last_page_of_log((uint16_t)log_num);
} else {
end_page = find_last_page_of_log((uint16_t)log_num);
start_page = end_page + 1;
}
} else {
if(log_num==1) {
StartRead(df_NumPages);
if(GetFileNumber() == 0xFFFF) {
start_page = 1;
} else {
start_page = find_last_page() + 1;
}
} else {
if(log_num == find_last_log() - num + 1) {
start_page = find_last_page() + 1;
} else {
look = log_num-1;
do {
start_page = find_last_page_of_log(look) + 1;
look--;
} while (start_page <= 0 && look >=1);
}
}
}
if (start_page == df_NumPages+1 || start_page == 0) {
start_page = 1;
}
end_page = find_last_page_of_log(log_num);
if (end_page == 0) {
end_page = start_page;
}
}
// This function starts a new log file in the DataFlash
void DataFlash_Block::start_new_log(void)
{
uint16_t last_page = find_last_page();
StartRead(last_page);
//Serial.print("last page: "); Serial.println(last_page);
//Serial.print("file #: "); Serial.println(GetFileNumber());
//Serial.print("file page: "); Serial.println(GetFilePage());
if(find_last_log() == 0 || GetFileNumber() == 0xFFFF) {
SetFileNumber(1);
StartWrite(1);
//Serial.println("start log from 0");
return;
}
// Check for log of length 1 page and suppress
if(GetFilePage() <= 1) {
SetFileNumber(GetFileNumber()); // Last log too short, reuse its number
StartWrite(last_page); // and overwrite it
//Serial.println("start log from short");
} else {
if(last_page == 0xFFFF) last_page=0;
SetFileNumber(GetFileNumber()+1);
StartWrite(last_page + 1);
//Serial.println("start log normal");
}
}
// This function starts a new log file in the DataFlash
uint16_t DataFlash_Block::start_new_log(void)
{
uint16_t last_page = find_last_page();
StartRead(last_page);
//Serial.print("last page: "); Serial.println(last_page);
//Serial.print("file #: "); Serial.println(GetFileNumber());
//Serial.print("file page: "); Serial.println(GetFilePage());
if(find_last_log() == 0 || GetFileNumber() == 0xFFFF) {
SetFileNumber(1);
StartWrite(1);
//Serial.println("start log from 0");
log_write_started = true;
return 1;
}
uint16_t new_log_num;
// Check for log of length 1 page and suppress
if(GetFilePage() <= 1) {
new_log_num = GetFileNumber();
// Last log too short, reuse its number
// and overwrite it
SetFileNumber(new_log_num);
StartWrite(last_page);
} else {
new_log_num = GetFileNumber()+1;
if (last_page == 0xFFFF) {
last_page=0;
}
SetFileNumber(new_log_num);
StartWrite(last_page + 1);
}
log_write_started = true;
return new_log_num;
}
// This funciton finds the last log number
uint16_t DataFlash_Block::find_last_log(void)
{
uint16_t last_page = find_last_page();
StartRead(last_page);
return GetFileNumber();
}