自学教程：C++ GetFileNumber函数代码示例

// This function starts a new log file in the DataFlashvoid 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 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 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;    }}

void InitDebugLine(    dw_client                   cli,    const char                  *source_filename,    char                        *inc_list,    unsigned                    inc_list_len ){    stmt_prologue prol = {        0,        DWARF_IMPL_VERSION,        sizeof( stmt_prologue )                - offsetof( stmt_prologue, minimum_instruction_length ),        DW_MIN_INSTR_LENGTH,        0,        DWLINE_BASE,        DWLINE_RANGE,        DWLINE_OPCODE_BASE,        {   /* LEB128 args  - Instruction op-code       */            0,              /* DW_LNS_copy              */            1,              /* DW_LNS_advance           */            1,              /* DW_LNS_advance_line      */            1,              /* DW_LNS_set_file          */            1,              /* DW_LNS_set_column        */            0,              /* DW_LNS_negate_stmt       */            0,              /* DW_LNS_set_basic_block   */            0,              /* DW_LNS_const_add_pc      */            0               /* DW_LNS_fixed_advance_pc  */            /*            //  GNU sets the last entry to 1. This is (maybe?) incorrect as the DW_LNS_fixed_advance_pc            //  opcode has a fixed uhalf (uint_16)argument, not a (U)LEB128 argument.            */        }    };    static uint_8 const terminators[] = {0,0};    prol.prologue_length += inc_list_len + 2;   // +2 for 2 list terminators    cli->debug_line.files = NULL;    cli->debug_line.addr = 0;    cli->debug_line.line = 1;    cli->debug_line.column = 0;    cli->debug_line.is_stmt = 0;    cli->debug_line.end_sequence = 0;    /* write the prologue */    CLIWrite( DW_DEBUG_LINE, (char*)&prol, sizeof( prol ) );    if( inc_list != 0 ) {       // write the include list        CLIWrite( DW_DEBUG_LINE, inc_list, inc_list_len );    }    CLIWrite( DW_DEBUG_LINE, terminators, sizeof(terminators) );    /* and put out the source filename */    GetFileNumber( cli, source_filename );}

static void ChecksumAddLump(md5_context_t *md5_context, lumpinfo_t *lump){    char buf[9];    strncpy(buf, lump->name, 8);    buf[8] = '/0';    MD5_UpdateString(md5_context, buf);    MD5_UpdateInt32(md5_context, GetFileNumber(lump->wad_file));    MD5_UpdateInt32(md5_context, lump->position);    MD5_UpdateInt32(md5_context, lump->size);}

void DWENTRY DWSetFile(    dw_client                   cli,    const char                  *filename ){    uint_8                      buf[ 1 + MAX_LEB128 ];    uint_8                      *end;    _Validate( filename != NULL );    buf[0] = DW_LNS_set_file;    end = LEB128( buf + 1, GetFileNumber( cli, filename ) );    CLIWrite( DW_DEBUG_LINE, buf, end - buf );}

// This function starts a new log file in the DataFlashuint16_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;}