ddn.data.xml.stream

Streaming (pull) parsing and event model entrypoints.

enum XmlStreamStatus

struct XmlIncrementalReaderOptions XmlReaderOptions

class XmlIncrementalReader XmlReader

Types 5

enumXmlStreamStatus

Status codes for the incremental streaming reader (XmlIncrementalReader).

The reader is always in exactly one of these states:

NEED_MORE_DATA — no event is available; the caller must feed() more bytes.
READY — an event is available via front().
END_OF_STREAM — markEndOfStream() was called and all input has been consumed.

END_OF_STREAM is terminal: once entered, no further operation changes the status. READY is transient: a subsequent advance() transitions to one of the other states.

NEED_MORE_DATANo event available; caller must `feed()` more bytes.

READYAn event is available via `front()`.

END_OF_STREAM`markEndOfStream()` was called and all input has been consumed.

structXmlReaderOptions

Options controlling XmlReader behavior.

Fields

bool substituteEntitiesIf `true`, decode entity references in text and attribute values.

bool forbidDoctypeIf `true`, reject `DOCTYPE` declarations.

classXmlReader

A pull-style streaming XML reader.

The reader is an input range over XmlEvent.

Fields

private XmlLexer _lexer

private XmlParserLimits _limits

private XmlEvent _front

private bool _empty

private XmlReaderOptions _options

private TokenProcessingState _state

private size_t _attributeIndex

Methods

bool empty() @property const @safe nothrowReturns `true` when the reader reached end-of-input.

const(XmlEvent) front() @property ref const @safe nothrowReturns the current event.

XmlReader save() @property @safeSaves the current state of the reader.

void popFront() @safeAdvances to the next event.

size_t depth() @property const @safe nothrowReturns the current reader depth.

bool isEmptyElement() @property const @safe nothrowReturns `true` if the current event is a `START_ELEMENT` for an empty element.

bool onAttribute() @property const @safe nothrowReturns `true` if the reader is positioned on an attribute of the current `START_ELEMENT`.

bool moveToFirstAttribute() @safe nothrowMoves to the first attribute on the current `START_ELEMENT`.

bool moveToNextAttribute() @safe nothrowMoves to the next attribute.

void moveToElement() @safe nothrowMoves back to the element from attribute position.

string readString() @safeReturns the string value of the current event's content. If on STARTELEMENT, it reads until matching ENDELEMENT and returns concatenated text.

long readLong() @safeReads the current element content as a long.

double readDouble() @safeReads the current element content as a double.

bool readBool() @safeReads the current element content as a boolean.

string readInnerXml() @safeReads the inner XML content of the current element.

string readOuterXml() @safeReads the current element and its content as XML.

void writeEvent(XmlStreamWriter writer, ref const(XmlEvent) ev) @safe

const(XmlEventAttribute) attribute() @property ref const @safe nothrowReturns the current attribute.

string name() @property const @safe nothrowReturns the current node name (`prefix:local` or `local`).

string prefix() @property const @safe nothrowReturns the current node prefix.

string local() @property const @safe nothrowReturns the current node local name.

string namespaceUri() @property const @safe nothrowReturns the current node namespace URI.

size_t attributeCount() @property const @safe nothrowReturns the attribute count for the current `START_ELEMENT`.

string getAttribute(string qname) const @safe nothrowLooks up an attribute value by lexical name.

string getAttributeNS(string uri, string localName) const @safe nothrowLooks up an attribute value by expanded name `{namespaceUri, local}`.

bool moveToAttributeNS(string uri, string localName) @safe nothrowMoves to an attribute by expanded name `{namespaceUri, local}`.

void advance() @safe

Constructors

this()

this(
          string input,
          string systemId =  "",
          size_t maxExpandedBytes =  0,
          XmlReaderOptions options =  XmlReaderOptions.init)

Constructs a reader over `input`.

structXmlIncrementalReaderOptions

Options controlling XmlIncrementalReader behavior.

Fields

bool substituteEntitiesIf `true`, decode entity references in text and attribute values.

bool forbidDoctypeIf `true`, reject `DOCTYPE` declarations.

classXmlIncrementalReader

An incremental (streaming) pull-style XML reader that accepts data in chunks.

Unlike XmlReader, which requires the entire XML input up front, this reader maintains an internal growable buffer and supports the feed() / compact() / markEndOfStream() lifecycle required for streaming parsing.

The reader operates as an explicit pump loop:

auto reader = new XmlIncrementalReader();
while (reader.status() == XmlStreamStatus.NEED_MORE_DATA) {
   auto chunk = socket.receive(buffer[]);
   if (chunk.length == 0) { reader.markEndOfStream(); break; }
   reader.feed(chunk);
   while (reader.advance() == XmlStreamStatus.READY) {
       processEvent(reader.front());
   }
}

Ownership: Every string field in XmlEvent and its sub-fields is owned

storage, not a slice into the internal buffer. Event strings remain valid until the reader is destroyed. compact() and feed() do not invalidate previously returned event strings.

Status model:

NEED_MORE_DATA — no event available; caller must feed() more bytes.
READY — an event is available via front().
END_OF_STREAM — terminal; markEndOfStream() was called and all input

has been consumed.

ForwardRange / save() are explicitly excluded from the initial release.

Fields

private XmlIncrementalLexer _lexer

private XmlParserLimits _limits

private XmlEvent _front

private XmlStreamStatus _status

private bool _eos

private XmlIncrementalReaderOptions _options

private TokenProcessingState _state

Methods

void feed(const(char)[] chunk) @safeAppends `chunk` to the internal unread buffer.

void markEndOfStream() @safe pure nothrowSignals that no more data will be fed.

XmlStreamStatus status() const @safe pure nothrowReturns the current reader status.

bool ready() const @safe pure nothrowReturns `true` when an event is available via `front()`.

const(XmlEvent) front() ref const @safe nothrowReturns the current event.

XmlStreamStatus advance() @safeAttempts to produce the next event.

void compact() @safe pure nothrowMoves unread bytes to the front of the internal buffer to reclaim space.

size_t depth() @property const @safe nothrowReturns the current reader depth.

bool isEmptyElement() @property const @safe nothrowReturns `true` if the current event is a `START_ELEMENT` for an empty element.

Constructors

this(string systemId =  "",
          XmlIncrementalReaderOptions options =  XmlIncrementalReaderOptions.init)

Constructs an incremental reader.