// 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(); }