IDataSourceStream¶
-
class
IDataSourceStream: public Stream¶ Base class for read-only stream.
Subclassed by FSTR::Stream, IFS::FWFS::ArchiveStream, MultiStream, ReadWriteStream, SectionStream, StreamTransformer, TemplateStream, UrlencodedOutputStream
Public Functions
-
virtual StreamType
getStreamType() const¶ Get the stream type.
- Return Value
StreamType: The stream type.
-
virtual bool
isValid() const¶ Determine if the stream object contains valid data.
- Note
Where inherited classes are initialised by constructor this method indicates whether that was successful or not (e.g. FileStream)
- Return Value
bool: true if valid, false if invalid
-
size_t
readBytes(char *buffer, size_t length)¶ Read chars from stream into buffer.
Terminates if length characters have been read or timeout (see setTimeout). Returns the number of characters placed in the buffer (0 means no valid data found).
- Note
Inherited classes may provide more efficient implementations without timeout.
-
virtual uint16_t
readMemoryBlock(char *data, int bufSize) = 0¶ Read a block of memory.
- Parameters
data: Pointer to the data to be readbufSize: Quantity of chars to read
- Return Value
uint16_t: Quantity of chars read
-
int
read()¶ Read one character and moves the stream pointer.
- Return Value
The: character that was read or -1 if none is available
-
int
peek()¶ Read a character without advancing the stream pointer.
- Return Value
int: The character that was read or -1 if none is available
-
virtual int
seekFrom(int offset, SeekOrigin origin)¶ Change position in stream.
- Note
This method is implemented by streams which support random seeking, such as files and memory streams.
- Parameters
offset:origin:
- Return Value
New: position, < 0 on error
-
virtual bool
seek(int len)¶ Move read cursor.
- Parameters
len: Relative cursor adjustment
- Return Value
bool: True on success.
-
virtual bool
isFinished() = 0¶ Check if all data has been read.
- Return Value
bool: True on success.
-
virtual int
available()¶ Return the total length of the stream.
- Return Value
int: -1 is returned when the size cannot be determined
-
size_t
write(uint8_t charToWrite)¶ From Stream class: We don’t write using this stream.
- Parameters
charToWrite:
-
int
length()¶ Return the total length of the stream.
- Return Value
int: -1 is returned when the size cannot be determined
-
virtual String
id() const¶ Returns unique id of the resource.
- Return Value
String: the unique id of the stream.
-
virtual String
getName() const¶ Returns name of the resource.
- Note
Commonly used to obtain name of file
- Return Value
-
virtual MimeType
getMimeType() const¶ Get MIME type for stream content.
- Return Value
MimeType:
-
String
readString(size_t maxLen)¶ Overrides Stream method for more efficient reading.
- Note
Stream position is updated by this call
-
virtual bool
moveString(String &s)¶ Memory-based streams may be able to move content into a String.
If the operation is not supported by the stream,
swill be invalidated and false returned.- Parameters
s: String object to move data into
- Return Value
bool: true on success, false if there’s a problem.
Because a String object must have a NUL terminator, this will be appended if there is sufficient capacity. In this case, the method returns true.
If there is no capacity to add a NUL terminator, then the final character of stream data will be replaced with a NUL. The method returns false to indicate this.
-
virtual StreamType