--- a/nbproject/configurations.xml Sat Jun 12 22:37:44 2021 +0200
+++ b/nbproject/configurations.xml Sat Jun 19 12:59:07 2021 +0200
@@ -50,6 +50,7 @@
<in>BasicASN1Reader.h</in>
<in>DOMBuildingXMLContentHandler.h</in>
<in>GenericASN1ContentHandler.h</in>
+ <in>TransactionalBuffer.h</in>
<in>XMLContentHandler.h</in>
</df>
<in>XMLDocumentConstructor.h</in>
@@ -132,6 +133,8 @@
tool="3"
flavor2="0">
</item>
+ <item path="src/lib/TransactionalBuffer.h" ex="false" tool="3" flavor2="0">
+ </item>
<item path="src/lib/XMLContentHandler.h" ex="false" tool="3" flavor2="0">
</item>
<item path="src/relpipe-in-xmltable.cpp" ex="false" tool="1" flavor2="0">
@@ -195,6 +198,8 @@
tool="3"
flavor2="0">
</item>
+ <item path="src/lib/TransactionalBuffer.h" ex="false" tool="3" flavor2="0">
+ </item>
<item path="src/lib/XMLContentHandler.h" ex="false" tool="3" flavor2="0">
</item>
<item path="src/relpipe-in-xmltable.cpp" ex="false" tool="1" flavor2="0">
--- a/src/XMLDocumentConstructor.h Sat Jun 12 22:37:44 2021 +0200
+++ b/src/XMLDocumentConstructor.h Sat Jun 19 12:59:07 2021 +0200
@@ -23,6 +23,7 @@
#include "lib/BasicASN1Reader.h"
#include "lib/GenericASN1ContentHandler.h"
#include "lib/DOMBuildingXMLContentHandler.h"
+#include "lib/TransactionalBuffer.h"
namespace relpipe {
namespace in {
@@ -50,10 +51,17 @@
reader.addHandler(asn1handler);
- // TODO: buffering? (reader itself also buffers)
- for (char ch = input->get(); input->good(); ch = input->get()) reader.write(&ch, 1);
+ try {
+ // TODO: buffering? (reader itself also buffers)
+ for (char ch = input->get(); input->good(); ch = input->get()) reader.write(&ch, 1);
+ } catch (const relpipe::in::asn1::lib::TransactionalBuffer::WriteBufferOverflowException& e) {
+ // TODO: avoid leaky abstraction and use different exception
+ throw relpipe::writer::RelpipeWriterException(L"Transactional buffer for ASN.1 input is too small");
+ }
reader.close();
+
+ if (parser->get_document()->get_root_node() == nullptr) throw relpipe::writer::RelpipeWriterException(L"Empty ASN.1 input"); // TODO: move to common class
}
};
--- a/src/lib/AbstractParser.cpp Sat Jun 12 22:37:44 2021 +0200
+++ b/src/lib/AbstractParser.cpp Sat Jun 19 12:59:07 2021 +0200
@@ -16,6 +16,7 @@
*/
#include "AbstractParser.h"
+#include "TransactionalBuffer.h"
namespace relpipe {
namespace in {
@@ -24,7 +25,9 @@
class AbstractParserImpl {
private:
+ friend AbstractParser;
AbstractParser* interface;
+ TransactionalBuffer buffer;
public:
AbstractParserImpl(AbstractParser* interface) : interface(interface) {
@@ -43,12 +46,15 @@
}
void AbstractParser::write(const char* buffer, const size_t length) {
- // TODO: update pointers and positions
try {
+ // TODO: do not write to the buffer, just append in read()/peek() and write just the part that was not read during this cycle
+ implementation->buffer.write(buffer, length);
+
// TODO: call an overridable method to get preferred minimum block size and run cycle only if we have enough data or EOF
+ // and/or remember the length of last failed (rollbacked) read() call
update();
commit();
- } catch (const AbstractParser::ReadBufferUnderflowException& e) {
+ } catch (const TransactionalBuffer::ReadBufferUnderflowException& e) {
rollback();
} catch (const AbstractParser::ExplicitRollbackException& e) {
rollback();
@@ -56,20 +62,24 @@
}
void AbstractParser::close() {
+ // TODO: check remaining data + call update() or just let parsers override this method?
}
void AbstractParser::rollback() {
- // FIXME: store content of the current buffer + update pointers and positions
// TODO: notify rollback listeners? (they can monitor the performance / frequency of rollbacks)
+ implementation->buffer.rollbackRead();
}
void AbstractParser::commit() {
+ implementation->buffer.commitRead();
}
void AbstractParser::read(char* buffer, const size_t length) {
+ implementation->buffer.read(buffer, length);
}
void AbstractParser::peek(char* buffer, const size_t length) {
+ implementation->buffer.read(buffer, length);
}
}
--- a/src/lib/AbstractParser.h Sat Jun 12 22:37:44 2021 +0200
+++ b/src/lib/AbstractParser.h Sat Jun 19 12:59:07 2021 +0200
@@ -64,14 +64,6 @@
AbstractParser();
/**
- * Is thrown from read() and peak() methods if there are not enough data.
- * Interrupts current update() cycle and causes rollback.
- */
- class ReadBufferUnderflowException {
- // TODO: common super-class for exceptions, hidden implementation
- };
-
- /**
* May be thrown from the update() method in order to cancel currenty cycle and do explicit rollback.
* Same data will be processed in the next cycle.
*/
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/TransactionalBuffer.h Sat Jun 19 12:59:07 2021 +0200
@@ -0,0 +1,128 @@
+/**
+ * Relational pipes
+ * Copyright © 2021 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <string>
+#include <exception>
+#include <cstring>
+
+#include "AbstractParser.h"
+
+namespace relpipe {
+namespace in {
+namespace asn1 {
+namespace lib {
+
+class TransactionalBuffer {
+private:
+ char* buffer;
+ size_t bufferSize;
+ bool hasData = false;
+ size_t writePosition = 0;
+ // size_t writePositionCommited = 0; // TODO: transactions also on the writing side?
+ size_t readPosition = 0;
+ size_t readPositionCommited = 0;
+
+ size_t availableForReading() {
+ if (readPosition < writePosition) return writePosition - readPosition;
+ else if (readPosition > writePosition) return bufferSize - readPosition + writePosition;
+ else if (hasData) return bufferSize;
+ else return 0;
+ }
+
+ size_t availableForWriting() {
+ if (readPositionCommited < writePosition) return bufferSize - writePosition + readPositionCommited;
+ else if (readPositionCommited > writePosition) return readPositionCommited - writePosition;
+ else if (hasData) return 0;
+ else return bufferSize;
+ }
+
+public:
+
+ /**
+ * Is thrown from read() and peak() methods if there are not enough data.
+ * Interrupts current update() cycle and causes rollback.
+ */
+ class ReadBufferUnderflowException {
+ // TODO: common super-class for exceptions, hidden implementation
+ };
+
+ /**
+ * Is thrown from write() method of the buffer when there is not enough space.
+ * Interrupts whole process.
+ */
+ class WriteBufferOverflowException {
+ };
+
+ TransactionalBuffer(size_t initialSize = 4096) : bufferSize(initialSize) {
+ // TODO: initial size + resize + hard upper limit
+ buffer = (char*) malloc(bufferSize);
+ }
+
+ virtual ~TransactionalBuffer() {
+ free(buffer);
+ }
+
+ void write(const char* inputBuffer, const size_t length) {
+ if (length == 0) return;
+ if (length > availableForWriting()) throw WriteBufferOverflowException(); // TODO: optional resize
+
+ hasData = true;
+
+ const size_t a = std::min(length, bufferSize - writePosition);
+ const size_t b = length - a;
+
+ // TODO: map buffer twice in the memory in order to create a continuous area and avoid the second memcpy()?
+ memcpy(buffer + writePosition, inputBuffer, a);
+ memcpy(buffer, inputBuffer + a, b);
+
+ writePosition = (writePosition + length) % bufferSize;
+ }
+
+ void read(char* outputBuffer, const size_t length) {
+ if (length == 0) return;
+
+ peek(outputBuffer, length);
+ readPosition = (readPosition + length) % bufferSize;
+ hasData = readPosition != writePosition;
+ }
+
+ void peek(char* outputBuffer, const size_t length) {
+ if (length == 0) return;
+ if (length > availableForReading()) throw ReadBufferUnderflowException();
+
+ const size_t a = std::min(length, bufferSize - readPosition);
+ const size_t b = length - a;
+
+ memcpy(outputBuffer, buffer + readPosition, a);
+ memcpy(outputBuffer + a, buffer, b);
+ }
+
+ void commitRead() {
+ readPositionCommited = readPosition;
+ }
+
+ void rollbackRead() {
+ readPosition = readPositionCommited;
+ }
+};
+
+
+}
+}
+}
+}