Fix file delete and write

prodos/directory.go

@@ -110,7 +110,6 @@ func GetFreeFileEntryInDirectory(file *os.File, directory string) (FileEntry, er
 }
 
 func getFileEntriesInDirectory(file *os.File, blockNumber int, currentPath int, paths []string) (DirectoryHeader, []FileEntry) {
-
 	buffer := ReadBlock(file, blockNumber)
 
 	directoryHeader := parseDirectoryHeader(buffer, blockNumber)
@@ -281,8 +280,10 @@ func parseDirectoryHeader(buffer []byte, blockNumber int) DirectoryHeader {
 	return directoryEntry
 }
 
-func writeDirectoryHeader(file *os.File, directoryHeader DirectoryHeader, blockNumber int) {
+func writeDirectoryHeader(file *os.File, directoryHeader DirectoryHeader) {
-	buffer := ReadBlock(file, blockNumber)
+	buffer := ReadBlock(file, directoryHeader.StartingBlock)
+	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))
@@ -291,5 +292,5 @@ func writeDirectoryHeader(file *os.File, directoryHeader DirectoryHeader, blockN
 	}
 	buffer[0x25] = byte(directoryHeader.ActiveFileCount & 0x00FF)
 	buffer[0x26] = byte(directoryHeader.ActiveFileCount >> 8)
-	file.WriteAt(buffer, int64(blockNumber*512))
+	WriteBlock(file, directoryHeader.StartingBlock, buffer)
 }

prodos/file.go

@@ -2,7 +2,6 @@ package prodos
 
 import (
 	"errors"
-	"fmt"
 	"os"
 	"strings"
 	"time"
@@ -31,7 +30,10 @@ func LoadFile(file *os.File, path string) ([]byte, error) {
 func WriteFile(file *os.File, path string, fileType int, auxType int, buffer []byte) error {
 	directory, fileName := GetDirectoryAndFileNameFromPath(path)
 
-	DeleteFile(file, path)
+	existingFileEntry, _ := GetFileEntry(file, path)
+	if existingFileEntry.StorageType != StorageDeleted {
+		DeleteFile(file, path)
+	}
 
 	// get list of blocks to write file to
 	blockList := createBlockList(file, len(buffer))
@@ -53,13 +55,12 @@ func WriteFile(file *os.File, path string, fileType int, auxType int, buffer []b
 
 		// write index block with pointers to data blocks
 		indexBuffer := make([]byte, 512)
-		for i := 1; i < 256; i++ {
+		for i := 0; i < 256; i++ {
-			if i < len(blockList) {
+			if i < len(blockList)-1 {
-				indexBuffer[i] = byte(blockList[i] & 0x00FF)
+				indexBuffer[i] = byte(blockList[i+1] & 0x00FF)
-				indexBuffer[i+256] = byte(blockList[i] >> 8)
+				indexBuffer[i+256] = byte(blockList[i+1] >> 8)
 			}
 		}
-		fmt.Println("writing index block")
 		WriteBlock(file, blockList[0], indexBuffer)
 
 		// write all data blocks
@@ -69,13 +70,10 @@ func WriteFile(file *os.File, path string, fileType int, auxType int, buffer []b
 		for i := 0; i < len(buffer); i++ {
 			blockBuffer[blockPointer] = buffer[i]
 			if blockPointer == 511 {
-				fmt.Printf("A i: %d, blockIndexNumber: %d, blockPointer: %d blockList[blockIndexNumber]: %d\n", i, blockIndexNumber, blockPointer, blockList[blockIndexNumber])
-				fmt.Println(blockIndexNumber)
 				WriteBlock(file, blockList[blockIndexNumber], blockBuffer)
 				blockPointer = 0
 				blockIndexNumber++
 			} else if i == len(buffer)-1 {
-				fmt.Printf("B i: %d, blockIndexNumber: %d, blockPointer: %d\n", i, blockIndexNumber, blockPointer)
 				for j := blockPointer; j < 512; j++ {
 					blockBuffer[j] = 0
 				}
@@ -87,6 +85,9 @@ func WriteFile(file *os.File, path string, fileType int, auxType int, buffer []b
 	}
 
 	// TODO: add tree file
+	if len(buffer) > 0x20000 {
+		return errors.New("Files > 128KB not supported yet.")
+	}
 
 	// update volume bitmap
 	volumeBitmap := ReadVolumeBitmap(file)
@@ -105,9 +106,54 @@ func WriteFile(file *os.File, path string, fileType int, auxType int, buffer []b
 	fileEntry.FileType = fileType
 	fileEntry.KeyPointer = blockList[0]
 	fileEntry.Access = 0b11100011
+	if len(blockList) == 1 {
+		fileEntry.StorageType = StorageSeedling
+	} else if len(blockList) <= 257 {
+		fileEntry.StorageType = StorageSapling
+	} else {
+		fileEntry.StorageType = StorageTree
+	}
 
 	writeFileEntry(file, fileEntry)
 
+	// increment file count
+	directoryHeaderBlock := ReadBlock(file, fileEntry.HeaderPointer)
+	directoryHeader := parseDirectoryHeader(directoryHeaderBlock, fileEntry.HeaderPointer)
+	directoryHeader.ActiveFileCount++
+	writeDirectoryHeader(file, directoryHeader)
+
+	return nil
+}
+
+func DeleteFile(file *os.File, path string) error {
+	fileEntry, err := GetFileEntry(file, path)
+	if err != nil {
+		return errors.New("File not found")
+	}
+	if fileEntry.StorageType == StorageDeleted {
+		return errors.New("File already deleted")
+	}
+
+	// free the blocks
+	blocks := getBlocklist(file, fileEntry)
+	volumeBitmap := ReadVolumeBitmap(file)
+	for i := 0; i < len(blocks); i++ {
+		freeBlockInVolumeBitmap(volumeBitmap, blocks[i])
+	}
+	writeVolumeBitmap(file, volumeBitmap)
+
+	// decrement the directory entry count
+	directoryBlock := ReadBlock(file, fileEntry.HeaderPointer)
+	directoryHeader := parseDirectoryHeader(directoryBlock, fileEntry.HeaderPointer)
+
+	directoryHeader.ActiveFileCount--
+	writeDirectoryHeader(file, directoryHeader)
+
+	// zero out directory entry
+	fileEntry.StorageType = 0
+	fileEntry.FileName = ""
+	writeFileEntry(file, fileEntry)
+
 	return nil
 }
 
@@ -120,8 +166,8 @@ func getBlocklist(file *os.File, fileEntry FileEntry) []int {
 	case StorageSapling:
 		index := ReadBlock(file, fileEntry.KeyPointer)
 		blocks[0] = fileEntry.KeyPointer
-		for i := 1; i < fileEntry.BlocksUsed-1; i++ {
+		for i := 0; i < fileEntry.BlocksUsed-1; i++ {
-			blocks[i] = int(index[i]) + int(index[i+256])*256
+			blocks[i+1] = int(index[i]) + int(index[i+256])*256
 		}
 	case StorageTree:
 		masterIndex := ReadBlock(file, fileEntry.KeyPointer)
@@ -163,10 +209,9 @@ func createBlockList(file *os.File, fileSize int) []int {
 
 func GetFileEntry(file *os.File, path string) (FileEntry, error) {
 	directory, fileName := GetDirectoryAndFileNameFromPath(path)
-
 	_, _, fileEntries := ReadDirectory(file, directory)
 
-	if fileEntries == nil {
+	if fileEntries == nil || len(fileEntries) == 0 {
 		return FileEntry{}, errors.New("File entry not found")
 	}
 
@@ -178,6 +223,10 @@ func GetFileEntry(file *os.File, path string) (FileEntry, error) {
 		}
 	}
 
+	if fileEntry.StorageType == StorageDeleted {
+		return FileEntry{}, errors.New("File not found")
+	}
+
 	return fileEntry, nil
 }
 
@@ -197,35 +246,3 @@ func GetDirectoryAndFileNameFromPath(path string) (string, string) {
 
 	return directory, fileName
 }
-
-func DeleteFile(file *os.File, path string) error {
-	fileEntry, err := GetFileEntry(file, path)
-	if err != nil {
-		return errors.New("File not found")
-	}
-	if fileEntry.StorageType == StorageDeleted {
-		return errors.New("File already deleted")
-	}
-
-	// free the blocks
-	blocks := getBlocklist(file, fileEntry)
-	volumeBitmap := ReadVolumeBitmap(file)
-	for i := 0; i < len(blocks); i++ {
-		freeBlockInVolumeBitmap(volumeBitmap, blocks[i])
-	}
-	writeVolumeBitmap(file, volumeBitmap)
-
-	// zero out directory entry
-	fileEntry.StorageType = 0
-	fileEntry.FileName = ""
-	writeFileEntry(file, fileEntry)
-
-	// decrement the directory entry count
-	directoryBlock := ReadBlock(file, fileEntry.HeaderPointer)
-	directoryHeader := parseDirectoryHeader(directoryBlock, fileEntry.HeaderPointer)
-
-	directoryHeader.ActiveFileCount--
-	writeDirectoryHeader(file, directoryHeader, fileEntry.HeaderPointer)
-
-	return nil
-}