File_Flush() | TFT & EPD Graphic Library 2

Syntax

File_Flush(), Bit

Overview

Return Values:

1 (Success): The flush operation was successful, and the file is safely updated.

0 (Error): An error occurred during the flush operation (e.g., read/write error).

Flush the File Buffer and Update File System

The File_Flush() command writes all data in the buffer to the file and updates the file size and FAT (File Allocation Table) clusters.
This ensures that any data held in the buffer is safely written to the SD card, making the file safe to remove.

How it works

Flushing the Buffer: When you write data to a file using File_WriteByte(), the data is stored in a buffer before being written to the SD card.
File_Flush() ensures that the buffer contents are written to the file and the file system (FAT) is updated accordingly.
File Size and FAT Update: After flushing, the file system updates the file's size and its FAT clusters.
This prevents any data from being lost if the card is removed and ensures the file's integrity.
Safe File Removal: After calling File_Flush(), the file is safe to remove. This action works similarly to closing and reopening the file but is much quicker.
It ensures that data is saved and avoids corruption in the event of unexpected removal of the SD card.
File Re-Opening: If you want to open a new file after calling File_Flush(), you'll need to close the current file first with File_Close().
After that, you can open a new file with File_Open(), File_Append(), or File_OpenAt(), or any other file opening function.

Example

File_Flush()

Notes

File Safety: File_Flush() ensures that the file is safe to remove or disconnect from the SD card, even without fully closing the file.
Use Cases: This is useful when you need to ensure data integrity, especially in embedded systems where file access is frequent and you want to minimize the risk of data corruption.

TftSetUp(0, 0) 'Set screen

TftResetScreen(BLACK) 'Reset screen

TftSetSndFont(0,0) 'Set Font0

While File_Init() <> cErrOK : Wend 'Initialize SD Card

TftPrintSndString("Sd Initialization OK",1,0,0,1,GREEN,BLACK,0) 'Confirm Initialize SD Card

File_TimeModified(5,11,24, 12,39,45) 'Set modified property

While File_Append("append.log") <> cErrOK : Wend 'Open file append.log to edit data

TftPrintSndString("Append append.log OK",1,0,2,1,GREEN,BLACK,0) 'Confirm append.log is open

sString = " world!" 'Load string with data to be written

For bCounter = 0 To 12

If sString[bCounter] = 0 Then Break 'break if end of string

File_WriteByte(sString[bCounter]) 'write data to append.Log

If File_Flush() = 1 Then

TftPrintSndString("Flush append.Log OK",1,0,3,1,GREEN,BLACK,0) 'confirm flush ok and good to remove card

Else

TftPrintSndString("Flush append.Log NO",1,0,3,1,GREEN,BLACK,0) 'flush not ok and not good to remove card

EndIf

File_Flush()

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