nl::Weave::TLV::TLVReader

Get the value of the current byte or UTF8 string element.

To determine the required input buffer size, call the GetLength() method before calling GetBytes().

Returns the type of the container within which the TLVReader is currently reading.

The GetContainerType() method returns the type of the TLV container within which the TLVReader is reading. If the TLVReader is positioned at the outer-most level of a TLV encoding (i.e. before, on or after the outer-most TLV element), the method will return kTLVType_NotSpecified.

Returns the control byte associated with current TLV element.

Ideally, nobody ever needs to know about the control byte and only the internal implementation of TLV should have access to it. But, nevertheless, having access to the control byte is helpful for debugging purposes by the TLVDebugUtilities (that try to decode the tag control byte when pretty printing the TLV buffer contents).

Get a pointer to the initial encoded byte of a TLV byte or UTF8 string element.

This method returns a direct pointer the encoded string value within the underlying input buffer. To succeed, the method requires that the entirety of the string value be present in a single buffer. Otherwise the method returns WEAVE_ERROR_TLV_UNDERRUN. This makes the method of limited use when reading data from multiple discontiguous buffers.

Returns the length of data associated with current TLV element.

Data length only applies to elements of type UTF8 string or byte string. For UTF8 strings, the value returned is the number of bytes in the string, not the number of characters.

Returns the total number of bytes read since the reader was initialized.

Gets the point in the underlying input buffer that corresponds to the reader's current position.

Returns the total number of bytes that can be read until the max read length is reached.

Get the value of the current byte or UTF8 string element as a null terminated string.

To determine the required input buffer size, call the GetLength() method before calling GetBytes(). The input buffer should be at least one byte bigger than the string length to accommodate the null character.

Returns the tag associated with current TLV element.

The value returned by GetTag() can be used with the tag utility functions (IsProfileTag(), IsContextTag(), ProfileIdFromTag(), etc.) to determine the type of tag and to extract various tag field values.

Returns the type of the current TLV element.

Initializes a TLVReader object from another TLVReader object.

Initializes a TLVReader object to read from a single input buffer.

Initializes a TLVReader object to read from a single PacketBuffer.

Parsing begins at the buffer's start position (buf->DataStart()) and continues until the end of the data in the buffer (as denoted by buf->Datalen()), or maxLen bytes have been parsed.

Initializes a TLVReader object to read from a one or more PacketBuffers.

Parsing begins at the initial buffer's start position (buf->DataStart()). If allowDiscontiguousBuffers is true, the reader will advance through the chain of buffers linked by their Next() pointers. Parsing continues until all data in the buffer chain has been consumed (as denoted by buf->Datalen()), or maxLen bytes have been parsed.

Advances the TLVReader object to the next TLV element to be read.

The Next() method positions the reader object on the next element in a TLV encoding that resides in the same containment context. In particular, if the reader is positioned at the outer-most level of a TLV encoding, calling Next() will advance the reader to the next, top-most element. If the reader is positioned within a TLV container element (a structure, array or path), calling Next() will advance the reader to the next member element of the container.

Since Next() constrains reader motion to the current containment context, calling Next() when the reader is positioned on a container element will advance over the container, skipping its member elements (and the members of any nested containers) until it reaches the first element after the container.

When there are no further elements within a particular containment context the Next() method will return a WEAVE_END_OF_TLV error and the position of the reader will remain unchanged.

Advances the TLVReader object to the next TLV element to be read, asserting the type and tag of the new element.

The Next(TLVType expectedType, uint64_t expectedTag) method is a convenience method that has the same behavior as Next(), but also verifies that the type and tag of the new TLV element match the supplied arguments.

Initializes a new TLVReader object for reading the members of a TLV container element.

The OpenContainer() method initializes a new TLVReader object for reading the member elements of a TLV container (a structure, array or path). When OpenContainer() is called, the current TLVReader object must be positioned on the container element to be read. The method takes as its sole argument a reference to a new reader that will be initialized to read the container. This reader is known as the container reader while the reader on which OpenContainer() is called is known as the parent reader.

When the OpenContainer() method returns, the container reader is positioned immediately before the first member of the container. Calling Next() on the container reader will advance through the members of the collection until the end is reached, at which point the reader will return WEAVE_END_OF_TLV.

While the container reader is open, applications must not make calls on or otherwise alter the state of the parent reader. Once an application has finished using the container reader it must close it by calling CloseContainer() on the parent reader, passing the container reader as an argument. Applications may close the container reader at any point, with or without reading all elements contained in the underlying container. After the container reader is closed, applications may continue their use of the parent reader.

The container reader inherits various configuration properties from the parent reader. These are:

• The implicit profile id (ImplicitProfileId)
• The application data pointer (AppData)
• The GetNextBuffer function pointer

Advances the TLVReader object to immediately after the current TLV element.

The Skip() method positions the reader object immediately after the current TLV element, such that a subsequent call to Next() will advance the reader to the following element. Like Next(), if the reader is positioned on a container element at the time of the call, the members of the container will be skipped. If the reader is not positioned on any element, its position remains unchanged.

Verifies that the TVLReader object is at the end of a TLV container.

The VerifyEndOfContainer() method verifies that there are no further TLV elements to be read within the current TLV container. This is a convenience method that is equivalent to calling Next() and checking for a return value of WEAVE_END_OF_TLV.

Clear the state of the TLVReader.

This method is used to position the reader before the first TLV, between TLVs or after the last TLV.

This is a private method that returns the TLVElementType from mControlByte.

GetElementHeadLength

WEAVE_ERROR GetElementHeadLength(
  uint8_t & elemHeadBytes
) const 

IsContainerOpen

bool IsContainerOpen(
  void
) const 

WEAVE_ERROR ReadData(
  uint8_t *buf,
  uint32_t len
)

WEAVE_ERROR ReadElement(
  void
)

uint64_t ReadTag(
  TLVTagControl tagControl,
  const uint8_t *& p
)

void SetContainerOpen(
  bool aContainerOpen
)

WEAVE_ERROR SkipData(
  void
)

WEAVE_ERROR SkipToEndOfContainer(
  void
)

WEAVE_ERROR VerifyElement(
  void
)

WEAVE_ERROR FailGetNextBuffer(
  TLVReader & reader,
  uintptr_t & bufHandle,
  const uint8_t *& bufStart,
  uint32_t & bufLen
)

WEAVE_ERROR GetNextPacketBuffer(
  TLVReader & reader,
  uintptr_t & bufHandle,
  const uint8_t *& bufStart,
  uint32_t & bufLen
)