mirror of
https://github.com/tjboldt/ProDOS-Utilities.git
synced 2024-12-28 11:32:05 +00:00
340 lines
10 KiB
Go
340 lines
10 KiB
Go
// Copyright Terence J. Boldt (c)2021-2023
|
|
// Use of this source code is governed by an MIT
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// This file provides access to read, write, delete
|
|
// fand parse directories on a ProDOS drive image
|
|
|
|
package prodos
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
// VolumeHeader from ProDOS
|
|
type VolumeHeader struct {
|
|
VolumeName string
|
|
CreationTime time.Time
|
|
ActiveFileCount int
|
|
BitmapStartBlock int
|
|
TotalBlocks int
|
|
NextBlock int
|
|
EntryLength int
|
|
EntriesPerBlock int
|
|
MinVersion int
|
|
Version int
|
|
}
|
|
|
|
// DirectoryHeader from ProDOS
|
|
type DirectoryHeader struct {
|
|
Name string
|
|
ActiveFileCount int
|
|
StartingBlock int
|
|
PreviousBlock int
|
|
NextBlock int
|
|
}
|
|
|
|
const (
|
|
// StorageDeleted signifies file is deleted
|
|
StorageDeleted = 0
|
|
// StorageSeedling signifies file is <= 512 bytes
|
|
StorageSeedling = 1
|
|
// StorageSapling signifies file is > 512 bytes and <= 128 KB
|
|
StorageSapling = 2
|
|
// StorageTree signifies file is > 128 KB and <= 16 MB
|
|
StorageTree = 3
|
|
// StoragePascal signifies pascal storage area
|
|
StoragePascal = 4
|
|
// StorageDirectory signifies directory
|
|
StorageDirectory = 13
|
|
)
|
|
|
|
// FileEntry from ProDOS
|
|
type FileEntry struct {
|
|
StorageType int
|
|
FileName string
|
|
FileType int
|
|
CreationTime time.Time
|
|
KeyPointer int
|
|
Version int
|
|
MinVersion int
|
|
BlocksUsed int
|
|
EndOfFile int
|
|
Access int
|
|
AuxType int
|
|
ModifiedTime time.Time
|
|
HeaderPointer int
|
|
DirectoryBlock int
|
|
DirectoryOffset int
|
|
}
|
|
|
|
// ReadDirectory reads the directory information from a specified path
|
|
// on a ProDOS image
|
|
func ReadDirectory(reader io.ReaderAt, path string) (VolumeHeader, DirectoryHeader, []FileEntry, error) {
|
|
buffer, err := ReadBlock(reader, 2)
|
|
if err != nil {
|
|
return VolumeHeader{}, DirectoryHeader{}, nil, err
|
|
}
|
|
|
|
volumeHeader := parseVolumeHeader(buffer)
|
|
|
|
if len(path) == 0 {
|
|
path = fmt.Sprintf("/%s", volumeHeader.VolumeName)
|
|
}
|
|
|
|
path = strings.ToUpper(path)
|
|
paths := strings.Split(path, "/")
|
|
|
|
directoryHeader, fileEntries, err := getFileEntriesInDirectory(reader, 2, 1, paths)
|
|
if err != nil {
|
|
return VolumeHeader{}, DirectoryHeader{}, nil, err
|
|
}
|
|
|
|
return volumeHeader, directoryHeader, fileEntries, nil
|
|
}
|
|
|
|
func getFreeFileEntryInDirectory(reader io.ReaderAt, directory string) (FileEntry, error) {
|
|
_, directoryHeader, _, err := ReadDirectory(reader, directory)
|
|
if err != nil {
|
|
return FileEntry{}, err
|
|
}
|
|
//DumpDirectoryHeader(directoryHeader)
|
|
blockNumber := directoryHeader.StartingBlock
|
|
buffer, err := ReadBlock(reader, blockNumber)
|
|
if err != nil {
|
|
return FileEntry{}, err
|
|
}
|
|
entryOffset := 43 // start at offset after header
|
|
entryNumber := 2 // header is essentially the first entry so start at 2
|
|
|
|
for {
|
|
if entryNumber > 13 {
|
|
blockNumber = int(buffer[2]) + int(buffer[3])*256
|
|
// if we ran out of blocks in the directory, return empty
|
|
// TODO: expand the directory to add more entries
|
|
if blockNumber == 0 {
|
|
return FileEntry{}, errors.New("no free file entries found")
|
|
}
|
|
// else read the next block in the directory
|
|
buffer, err = ReadBlock(reader, blockNumber)
|
|
if err != nil {
|
|
return FileEntry{}, nil
|
|
}
|
|
entryOffset = 4
|
|
entryNumber = 1
|
|
}
|
|
fileEntry := parseFileEntry(buffer[entryOffset:entryOffset+40], blockNumber, entryOffset)
|
|
|
|
if fileEntry.StorageType == StorageDeleted {
|
|
fileEntry.DirectoryBlock = blockNumber
|
|
fileEntry.DirectoryOffset = entryOffset
|
|
fileEntry.HeaderPointer = directoryHeader.StartingBlock
|
|
return fileEntry, nil
|
|
}
|
|
|
|
entryNumber++
|
|
entryOffset += 39
|
|
}
|
|
}
|
|
|
|
func getFileEntriesInDirectory(reader io.ReaderAt, blockNumber int, currentPath int, paths []string) (DirectoryHeader, []FileEntry, error) {
|
|
buffer, err := ReadBlock(reader, blockNumber)
|
|
if err != nil {
|
|
return DirectoryHeader{}, nil, err
|
|
}
|
|
|
|
directoryHeader := parseDirectoryHeader(buffer, blockNumber)
|
|
|
|
fileEntries := make([]FileEntry, directoryHeader.ActiveFileCount)
|
|
entryOffset := 43 // start at offset after header
|
|
activeEntries := 0
|
|
entryNumber := 2 // header is essentially the first entry so start at 2
|
|
|
|
nextBlock := directoryHeader.NextBlock
|
|
|
|
matchedDirectory := (currentPath == len(paths)-1) && (paths[currentPath] == directoryHeader.Name)
|
|
|
|
if !matchedDirectory && (currentPath == len(paths)-1) {
|
|
// path not matched by last path part
|
|
return DirectoryHeader{}, nil, errors.New("path not matched")
|
|
}
|
|
|
|
for {
|
|
if entryNumber > 13 {
|
|
entryOffset = 4
|
|
entryNumber = 1
|
|
if blockNumber == 0 {
|
|
return DirectoryHeader{}, nil, nil
|
|
}
|
|
buffer, err = ReadBlock(reader, nextBlock)
|
|
if err != nil {
|
|
return DirectoryHeader{}, nil, err
|
|
}
|
|
nextBlock = int(buffer[2]) + int(buffer[3])*256
|
|
}
|
|
fileEntry := parseFileEntry(buffer[entryOffset:entryOffset+40], blockNumber, entryOffset)
|
|
|
|
if fileEntry.StorageType != StorageDeleted {
|
|
if matchedDirectory && activeEntries == directoryHeader.ActiveFileCount {
|
|
return directoryHeader, fileEntries[0:activeEntries], nil
|
|
}
|
|
if matchedDirectory {
|
|
fileEntries[activeEntries] = fileEntry
|
|
} else if !matchedDirectory && fileEntry.FileType == 15 && paths[currentPath+1] == fileEntry.FileName {
|
|
return getFileEntriesInDirectory(reader, fileEntry.KeyPointer, currentPath+1, paths)
|
|
}
|
|
activeEntries++
|
|
}
|
|
|
|
entryNumber++
|
|
entryOffset += 39
|
|
}
|
|
}
|
|
|
|
func parseFileEntry(buffer []byte, blockNumber int, entryOffset int) FileEntry {
|
|
storageType := int(buffer[0] >> 4)
|
|
fileNameLength := int(buffer[0] & 15)
|
|
fileName := string(buffer[1 : fileNameLength+1])
|
|
fileType := int(buffer[16])
|
|
startingBlock := int(buffer[17]) + int(buffer[18])*256
|
|
blocksUsed := int(buffer[19]) + int(buffer[20])*256
|
|
endOfFile := int(buffer[21]) + int(buffer[22])*256 + int(buffer[23])*65536
|
|
creationTime := DateTimeFromProDOS(buffer[24:28])
|
|
version := int(buffer[28])
|
|
minVersion := int(buffer[29])
|
|
access := int(buffer[30])
|
|
auxType := int(buffer[31]) + int(buffer[32])*256
|
|
modifiedTime := DateTimeFromProDOS((buffer[33:37]))
|
|
headerPointer := int(buffer[0x25]) + int(buffer[0x26])*256
|
|
|
|
fileEntry := FileEntry{
|
|
StorageType: storageType,
|
|
FileName: fileName,
|
|
FileType: fileType,
|
|
CreationTime: creationTime,
|
|
Version: version,
|
|
MinVersion: minVersion,
|
|
KeyPointer: startingBlock,
|
|
BlocksUsed: blocksUsed,
|
|
EndOfFile: endOfFile,
|
|
Access: access,
|
|
AuxType: auxType,
|
|
ModifiedTime: modifiedTime,
|
|
HeaderPointer: headerPointer,
|
|
DirectoryBlock: blockNumber,
|
|
DirectoryOffset: entryOffset,
|
|
}
|
|
|
|
return fileEntry
|
|
}
|
|
|
|
func writeFileEntry(writer io.WriterAt, fileEntry FileEntry) {
|
|
buffer := make([]byte, 39)
|
|
buffer[0] = byte(fileEntry.StorageType)<<4 + byte(len(fileEntry.FileName))
|
|
for i := 0; i < len(fileEntry.FileName); i++ {
|
|
buffer[i+1] = fileEntry.FileName[i]
|
|
}
|
|
buffer[0x10] = byte(fileEntry.FileType)
|
|
buffer[0x11] = byte(fileEntry.KeyPointer & 0xFF)
|
|
buffer[0x12] = byte(fileEntry.KeyPointer >> 8)
|
|
buffer[0x13] = byte(fileEntry.BlocksUsed & 0xFF)
|
|
buffer[0x14] = byte(fileEntry.BlocksUsed >> 8)
|
|
buffer[0x15] = byte(fileEntry.EndOfFile & 0x0000FF)
|
|
buffer[0x16] = byte(fileEntry.EndOfFile & 0x00FF00 >> 8)
|
|
buffer[0x17] = byte(fileEntry.EndOfFile & 0xFF0000 >> 16)
|
|
creationTime := DateTimeToProDOS(fileEntry.CreationTime)
|
|
for i := 0; i < 4; i++ {
|
|
buffer[0x18+i] = creationTime[i]
|
|
}
|
|
buffer[0x1C] = byte(fileEntry.Version)
|
|
buffer[0x1D] = byte(fileEntry.MinVersion)
|
|
buffer[0x1E] = byte(fileEntry.Access)
|
|
buffer[0x1F] = byte(fileEntry.AuxType & 0x00FF)
|
|
buffer[0x20] = byte(fileEntry.AuxType >> 8)
|
|
modifiedTime := DateTimeToProDOS(fileEntry.CreationTime)
|
|
for i := 0; i < 4; i++ {
|
|
buffer[0x21+i] = modifiedTime[i]
|
|
}
|
|
buffer[0x25] = byte(fileEntry.HeaderPointer & 0x00FF)
|
|
buffer[0x26] = byte(fileEntry.HeaderPointer >> 8)
|
|
|
|
_, err := writer.WriteAt(buffer, int64(fileEntry.DirectoryBlock*512+fileEntry.DirectoryOffset))
|
|
if err != nil {
|
|
|
|
}
|
|
}
|
|
|
|
func parseVolumeHeader(buffer []byte) VolumeHeader {
|
|
nextBlock := int(buffer[2]) + int(buffer[3])*256
|
|
filenameLength := buffer[4] & 15
|
|
volumeName := string(buffer[5 : filenameLength+5])
|
|
creationTime := DateTimeFromProDOS(buffer[28:32])
|
|
version := int(buffer[32])
|
|
minVersion := int(buffer[33])
|
|
entryLength := int(buffer[35])
|
|
entriesPerBlock := int(buffer[36])
|
|
fileCount := int(buffer[37]) + int(buffer[38])*256
|
|
bitmapBlock := int(buffer[39]) + int(buffer[40])*256
|
|
totalBlocks := int(buffer[41]) + int(buffer[42])*256
|
|
|
|
if minVersion > 0 {
|
|
panic("Unsupported ProDOS version")
|
|
}
|
|
|
|
volumeHeader := VolumeHeader{
|
|
VolumeName: volumeName,
|
|
CreationTime: creationTime,
|
|
ActiveFileCount: fileCount,
|
|
BitmapStartBlock: bitmapBlock,
|
|
TotalBlocks: totalBlocks,
|
|
NextBlock: nextBlock,
|
|
EntriesPerBlock: entriesPerBlock,
|
|
EntryLength: entryLength,
|
|
MinVersion: minVersion,
|
|
Version: version,
|
|
}
|
|
return volumeHeader
|
|
}
|
|
|
|
func parseDirectoryHeader(buffer []byte, blockNumber int) DirectoryHeader {
|
|
previousBlock := int(buffer[0x00]) + int(buffer[0x01])*256
|
|
nextBlock := int(buffer[0x02]) + int(buffer[0x03])*256
|
|
filenameLength := buffer[0x04] & 15
|
|
name := string(buffer[0x05 : filenameLength+0x05])
|
|
fileCount := int(buffer[0x25]) + int(buffer[0x26])*256
|
|
|
|
directoryEntry := DirectoryHeader{
|
|
PreviousBlock: previousBlock,
|
|
NextBlock: nextBlock,
|
|
StartingBlock: blockNumber,
|
|
Name: name,
|
|
ActiveFileCount: fileCount,
|
|
}
|
|
|
|
return directoryEntry
|
|
}
|
|
|
|
func writeDirectoryHeader(readerWriter ReaderWriterAt, directoryHeader DirectoryHeader) error {
|
|
buffer, err := ReadBlock(readerWriter, directoryHeader.StartingBlock)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
buffer[0x00] = byte(directoryHeader.PreviousBlock & 0x00FF)
|
|
buffer[0x01] = byte(directoryHeader.PreviousBlock >> 8)
|
|
buffer[0x02] = byte(directoryHeader.NextBlock & 0x00FF)
|
|
buffer[0x03] = byte(directoryHeader.NextBlock >> 8)
|
|
buffer[0x04] = buffer[0x04] | byte(len(directoryHeader.Name))
|
|
for i := 0; i < len(directoryHeader.Name); i++ {
|
|
buffer[0x05+i] = directoryHeader.Name[i]
|
|
}
|
|
buffer[0x25] = byte(directoryHeader.ActiveFileCount & 0x00FF)
|
|
buffer[0x26] = byte(directoryHeader.ActiveFileCount >> 8)
|
|
WriteBlock(readerWriter, directoryHeader.StartingBlock, buffer)
|
|
|
|
return nil
|
|
}
|