From c234027330fc6f4fc2317ac43e5b3e7278d2e462 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Mon, 23 Oct 2017 12:06:59 +0200
Subject: [PATCH] ENH: include memory streams
- these provide a similar functionality to string-streams, but operate
on a externally provided memory buffer which can be used to reduce
the amount of copying.
- classes were previously staged as part of the ADIOS community
repository.
---
applications/test/UIBufStream/Make/files | 3 +
applications/test/UIBufStream/Make/options | 2 +
.../test/UIBufStream/Test-UIBufStream.C | 88 ++++++
.../db/IOstreams/memory/BufStreamAllocator.H | 266 ++++++++++++++++++
.../db/IOstreams/memory/OCountStream.H | 230 +++++++++++++++
.../db/IOstreams/memory/UIBufStream.H | 168 +++++++++++
.../db/IOstreams/memory/UOBufStream.H | 190 +++++++++++++
7 files changed, 947 insertions(+)
create mode 100644 applications/test/UIBufStream/Make/files
create mode 100644 applications/test/UIBufStream/Make/options
create mode 100644 applications/test/UIBufStream/Test-UIBufStream.C
create mode 100644 src/OpenFOAM/db/IOstreams/memory/BufStreamAllocator.H
create mode 100644 src/OpenFOAM/db/IOstreams/memory/OCountStream.H
create mode 100644 src/OpenFOAM/db/IOstreams/memory/UIBufStream.H
create mode 100644 src/OpenFOAM/db/IOstreams/memory/UOBufStream.H
diff --git a/applications/test/UIBufStream/Make/files b/applications/test/UIBufStream/Make/files
new file mode 100644
index 0000000000..611f5337be
--- /dev/null
+++ b/applications/test/UIBufStream/Make/files
@@ -0,0 +1,3 @@
+Test-UIBufStream.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-UIBufStream
diff --git a/applications/test/UIBufStream/Make/options b/applications/test/UIBufStream/Make/options
new file mode 100644
index 0000000000..4e772fdf9d
--- /dev/null
+++ b/applications/test/UIBufStream/Make/options
@@ -0,0 +1,2 @@
+/* EXE_INC = -I$(LIB_SRC)/finiteVolume/lnInclude */
+/* EXE_LIBS = -lfiniteVolume */
diff --git a/applications/test/UIBufStream/Test-UIBufStream.C b/applications/test/UIBufStream/Test-UIBufStream.C
new file mode 100644
index 0000000000..f183d623ab
--- /dev/null
+++ b/applications/test/UIBufStream/Test-UIBufStream.C
@@ -0,0 +1,88 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2017 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM 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, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
+
+Description
+
+\*---------------------------------------------------------------------------*/
+
+#include "UIBufStream.H"
+#include "UOBufStream.H"
+#include "wordList.H"
+#include "IOstreams.H"
+#include "argList.H"
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+// Main program:
+
+int main(int argc, char *argv[])
+{
+ // Buffer storage
+ DynamicList<char> storage(1000);
+
+ UOBufStream obuf(storage);
+ obuf << 1002 << " " << "abcd" << " " << "def" << " " << 3.14159 << ";\n";
+
+ Info<<"formatted: " << obuf.size() << " chars" << endl;
+
+ // Match size
+ storage.resize(obuf.size());
+
+ Info<<"as string: " << string(storage.cdata(), storage.size()) << endl;
+
+ // Attach input buffer - could also do without previous resize
+
+ UIBufStream ibuf(storage, storage.size());
+
+ token t;
+
+ while (ibuf.good())
+ {
+ ibuf >> t;
+ if (t.good())
+ {
+ Info<<"token: " << t << endl;
+ }
+ }
+
+ Info<< nl << "Repeat..." << endl;
+ ibuf.rewind();
+
+ while (ibuf.good())
+ {
+ ibuf >> t;
+ if (t.good())
+ {
+ Info<<"token: " << t << endl;
+ }
+ }
+
+
+ Info<< "\nEnd\n" << endl;
+
+ return 0;
+}
+
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/db/IOstreams/memory/BufStreamAllocator.H b/src/OpenFOAM/db/IOstreams/memory/BufStreamAllocator.H
new file mode 100644
index 0000000000..0696e1a943
--- /dev/null
+++ b/src/OpenFOAM/db/IOstreams/memory/BufStreamAllocator.H
@@ -0,0 +1,266 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2016-2017 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM 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, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
+
+Class
+ Foam::BufStreamAllocator
+
+Description
+ Helper for memory buffer streams such as UIBufStream, UOBufStream
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef BufStreamAllocator_H
+#define BufStreamAllocator_H
+
+#include <type_traits>
+#include <sstream>
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+ Class memorybuf Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A streambuf class for using externally allocated memory for its buffer
+class memorybuf
+:
+ public std::streambuf
+{
+protected:
+
+ // Protected members
+
+ //- Set position pointer to relative position
+ virtual std::streampos seekoff
+ (
+ std::streamoff off,
+ std::ios_base::seekdir way,
+ std::ios_base::openmode which = std::ios_base::in|std::ios_base::out
+ )
+ {
+ const bool testin = which & std::ios_base::in;
+ const bool testout = which & std::ios_base::out;
+
+ if (way == std::ios_base::beg)
+ {
+ if (testin)
+ {
+ setg(eback(), eback(), egptr());
+ gbump(off);
+ }
+ if (testout)
+ {
+ setp(pbase(), epptr());
+ pbump(off);
+ }
+
+ return off;
+ }
+
+ if (way == std::ios_base::cur)
+ {
+ if (testin)
+ {
+ gbump(off);
+ }
+ if (testout)
+ {
+ pbump(off);
+ }
+ }
+ else if (way == std::ios_base::end)
+ {
+ if (testin)
+ {
+ gbump(off);
+ }
+ if (testout)
+ {
+ pbump(off);
+ }
+ }
+
+ if (testin)
+ {
+ return gptr() - eback();
+ }
+ if (testout)
+ {
+ return pptr() - pbase();
+ }
+
+ return -1;
+ }
+
+
+ //- Set position pointer to absolute position
+ virtual std::streampos seekpos
+ (
+ std::streampos pos,
+ std::ios_base::openmode which = std::ios_base::in|std::ios_base::out
+ )
+ {
+ return seekoff(pos, std::ios_base::beg, which);
+ }
+
+
+ //- Get sequence of characters
+ virtual std::streamsize xsgetn(char* s, std::streamsize n)
+ {
+ std::streamsize count = 0;
+
+ // some optimization could be possible here
+ while (count < n && gptr() < egptr())
+ {
+ *(s + count++) = *(gptr());
+ gbump(1);
+ }
+
+ return count;
+ }
+
+
+ //- Put sequence of characters
+ virtual std::streamsize xsputn(const char* s, std::streamsize n)
+ {
+ std::streamsize count = 0;
+
+ // some optimization could be possible here
+ while (count < n && pptr() < epptr())
+ {
+ *(pptr()) = *(s + count++);
+ pbump(1);
+ }
+
+ return count;
+ }
+
+
+public:
+
+ // Constructors
+
+ //- Construct for specified buffer
+ memorybuf(char* buffer, std::streamsize num)
+ {
+ setg(buffer, buffer, buffer + num);
+ setp(buffer, buffer + num);
+ }
+
+};
+
+
+/*---------------------------------------------------------------------------*\
+ Class BufStreamAllocator Declaration
+\*---------------------------------------------------------------------------*/
+
+//- An stream/stream-buffer allocator for external buffers
+template<class StreamType, bool Manage=false>
+class BufStreamAllocator
+{
+ // Private data
+
+ //- Storage
+ char *storage_;
+
+ //- The number of bytes in the storage
+ std::streamsize len_;
+
+ //- Reference to the underlying buffer
+ memorybuf buf_;
+
+protected:
+
+ // Protected data
+
+ typedef StreamType stream_type;
+
+ //- The stream pointer
+ stream_type stream_;
+
+
+ // Constructors
+
+ //- Construct with buffer and number of bytes
+ BufStreamAllocator(char *buffer, size_t nbytes)
+ :
+ storage_(buffer),
+ len_(nbytes),
+ buf_(storage_, len_),
+ stream_(&buf_)
+ {}
+
+
+ //- Destructor
+ ~BufStreamAllocator()
+ {
+ // Possible cleanup of storage
+ if (Manage && storage_)
+ {
+ delete storage_;
+ storage_ = nullptr;
+ }
+ }
+
+
+ // Protected Member Functions
+
+
+ //- Position of the get buffer
+ std::streampos tellg() const
+ {
+ return const_cast<stream_type&>(stream_).tellg();
+ }
+
+ //- Position of the put buffer
+ std::streampos tellp() const
+ {
+ return const_cast<stream_type&>(stream_).tellp();
+ }
+
+
+public:
+
+ // Public Member Functions
+
+ //- Move to buffer start, clear errors
+ void rewind()
+ {
+ stream_.rdbuf()->pubseekpos(0);
+ stream_.clear(); // for safety, clear any old errors
+ }
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/db/IOstreams/memory/OCountStream.H b/src/OpenFOAM/db/IOstreams/memory/OCountStream.H
new file mode 100644
index 0000000000..b3ce64b169
--- /dev/null
+++ b/src/OpenFOAM/db/IOstreams/memory/OCountStream.H
@@ -0,0 +1,230 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2016-2017 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM 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, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
+
+Class
+ Foam::OSCountStream
+
+Description
+ An output stream for calculating byte counts.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef OScountStream_H
+#define OScountStream_H
+
+#include "OSstream.H"
+#include <iostream>
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+ Class countstreambuf Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A streambuf class for determining byte counts
+class countstreambuf
+:
+ public std::streambuf
+{
+ // Private data
+
+ //- The number of bytes
+ std::streamsize n_;
+
+protected:
+ // Protected members
+
+ //- Put sequence of characters
+ virtual std::streamsize xsputn(const char* s, std::streamsize num)
+ {
+ n_ += num;
+ return num;
+ }
+
+
+ //- Set position pointer to absolute position
+ // For the counter, any positioning is ignored and it always acts like
+ // seekpos(0), which resets the count.
+ virtual std::streampos seekpos
+ (
+ std::streampos sp,
+ std::ios_base::openmode which = std::ios_base::in|std::ios_base::out
+ )
+ {
+ n_ = 0;
+ return 0;
+ }
+
+
+public:
+
+ // Constructors
+
+ //- Construct null
+ countstreambuf()
+ :
+ n_(0)
+ {}
+
+
+ // Access
+
+ //- Get number of bytes counted
+ std::streamsize size() const
+ {
+ return n_;
+ }
+};
+
+
+/*---------------------------------------------------------------------------*\
+ Class ocountstream Declaration
+\*---------------------------------------------------------------------------*/
+
+//- Trivial output stream for calculating byte counts
+// Since all output values are discarded, it can also be used as a /dev/null
+// output buffer as well
+class ocountstream
+:
+ virtual public std::ios,
+ public std::ostream
+{
+ // Private data
+
+ countstreambuf buf_;
+
+public:
+
+ // Constructors
+
+ //- Construct null
+ ocountstream()
+ :
+ std::ostream(&buf_)
+ {}
+
+
+ // Member Functions
+
+ // Access
+
+ //- This hides both signatures of std::basic_ios::rdbuf()
+ countstreambuf* rdbuf()
+ {
+ return &buf_;
+ }
+
+
+ //- Get number of bytes counted
+ std::streamsize size() const
+ {
+ return buf_.size();
+ }
+
+
+ //- Rewind the stream, reset the count
+ void rewind()
+ {
+ buf_.pubseekpos(0);
+ clear(); // for safety, clear any old errors
+ }
+};
+
+
+/*---------------------------------------------------------------------------*\
+ Class OCountStream Declaration
+\*---------------------------------------------------------------------------*/
+
+//- An output stream for calculating byte counts
+class OCountStream
+:
+ private ocountstream,
+ public OSstream
+{
+
+ // Private Member Functions
+
+ //- Disallow default bitwise copy construct
+ OCountStream(const OCountStream&) = delete;
+
+ //- Disallow default bitwise assignment
+ void operator=(const OCountStream&) = delete;
+
+public:
+
+ // Constructors
+
+ //- Construct and set stream status
+ OCountStream
+ (
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion
+ )
+ :
+ ocountstream(),
+ OSstream
+ (
+ static_cast<ocountstream&>(*this),
+ "output",
+ format,
+ version
+ )
+ {}
+
+
+ //- Destructor
+ ~OCountStream()
+ {}
+
+
+ // Member functions
+
+ // Access
+
+ //- Return the number of bytes counted
+ using ocountstream::size;
+
+
+ // Edit
+
+ //- Rewind the stream, reset the count, clearing any old errors
+ void rewind()
+ {
+ ocountstream::rewind();
+ setGood(); // resynchronize with internal state
+ }
+
+};
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/db/IOstreams/memory/UIBufStream.H b/src/OpenFOAM/db/IOstreams/memory/UIBufStream.H
new file mode 100644
index 0000000000..e02929f181
--- /dev/null
+++ b/src/OpenFOAM/db/IOstreams/memory/UIBufStream.H
@@ -0,0 +1,168 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2016-2017 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM 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, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
+
+Class
+ Foam::UIBufStream
+
+Description
+ Similar to IStringStream but using an externally managed buffer for its
+ input. This allows the input buffer to be filled (and refilled) from
+ various sources.
+
+ Note that this stream will normally be used as a "one-shot" reader.
+ Caution must be exercised that the referenced buffer remains valid and
+ without any intermediate resizing for the duration of the stream's use.
+
+ An example of possible use:
+ \code
+ DynamicList<char> buffer(4096); // allocate some large buffer
+
+ nread = something.read(buffer.data(),1024); // fill with content
+ buffer.setSize(nread); // content size
+
+ // construct dictionary, or something else
+ UIBufStream is(buffer)
+ dictionary dict1(is);
+
+ // sometime later
+ nread = something.read(buffer.data(),2048); // fill with content
+ buffer.setSize(nread); // content size
+
+ // without intermediate variable
+ dictionary dict2(UIBufStream(buffer)());
+ \endcode
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef UIBufStream_H
+#define UIBufStream_H
+
+#include "BufStreamAllocator.H"
+#include "ISstream.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+ Class UIBufStream Declaration
+\*---------------------------------------------------------------------------*/
+
+class UIBufStream
+:
+ public BufStreamAllocator<std::istream,false>,
+ public ISstream
+{
+ typedef BufStreamAllocator<std::istream,false> allocator_type;
+
+public:
+
+ // Constructors
+
+ //- Construct using specified buffer and number of bytes
+ UIBufStream
+ (
+ const char* buffer,
+ size_t nbytes,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion,
+ const Foam::string& name="input"
+ )
+ :
+ allocator_type(const_cast<char*>(buffer), nbytes),
+ ISstream(stream_, name, format, version)
+ {}
+
+
+ //- Construct using data area from a List and number of bytes
+ UIBufStream
+ (
+ const UList<char>& buffer,
+ label size,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion,
+ const Foam::string& name="input"
+ )
+ :
+ UIBufStream(buffer.cdata(), size, format,version,name)
+ {}
+
+
+ //- Construct using data area from a List and its inherent storage size
+ // Uses addressed size, thus no special treatment for a DynamicList
+ UIBufStream
+ (
+ const UList<char>& buffer,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion,
+ const Foam::string& name="input"
+ )
+ :
+ UIBufStream(buffer.cdata(), buffer.size(), format,version,name)
+ {}
+
+
+ //- Destructor
+ ~UIBufStream()
+ {}
+
+
+ // Member functions
+
+ //- Return the current get position in the buffer
+ std::streampos pos() const
+ {
+ return allocator_type::tellg();
+ }
+
+
+ //- Rewind the stream, clearing any old errors
+ virtual void rewind()
+ {
+ allocator_type::rewind();
+ setGood(); // resynchronize with internal state
+ }
+
+
+ // Member operators
+
+ //- A non-const reference to const Istream
+ // Needed for read-constructors where the stream argument is temporary
+ Istream& operator()() const
+ {
+ return const_cast<Istream&>(static_cast<const Istream&>(*this));
+ }
+
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/db/IOstreams/memory/UOBufStream.H b/src/OpenFOAM/db/IOstreams/memory/UOBufStream.H
new file mode 100644
index 0000000000..6a8df54e7a
--- /dev/null
+++ b/src/OpenFOAM/db/IOstreams/memory/UOBufStream.H
@@ -0,0 +1,190 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 2016-2017 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM 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, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
+
+Class
+ Foam::UOBufStream
+
+Description
+ Similar to OStringStream but using an externally managed buffer for
+ its output.
+
+ This allows the output buffer to be reused and can make it easier when
+ writing out data. It is the user's responsibility to ensure proper
+ synchronization in the sizes. Provided that the external buffer is large
+ enough that overflow does not occur, the following usage pattern
+ works.
+
+ \code
+ DynamicList<char> buffer(4096); // allocate some large buffer
+
+ {
+ UOBufStream os(buffer);
+ os << "content1" << " and more content";
+ buffer.setSize(os.size()); // synchronize sizes
+ }
+
+ something.write(buffer, buffer.size());
+ \endcode
+
+ Although the UOBufStream is quite lightweight, there may be cases
+ where it is preferable to reuse the stream as well.
+ \code
+ DynamicList<char> buffer(4096); // allocate some large buffer
+
+ UOBufStream os(buffer);
+ os << "content1" << " and more content";
+ buffer.setSize(os.size()); // synchronize sizes
+
+ something.write(buffer, buffer.size());
+
+ os.rewind();
+ os << "content2";
+ buffer.setSize(os.size()); // synchronize sizes
+
+ something.write(buffer, buffer.size());
+
+ // or simply using the output size directly (without sync)
+ os.rewind();
+ os << "content3";
+
+ something.write(buffer, os.size());
+ \endcode
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef UOBufStream_H
+#define UOBufStream_H
+
+#include "BufStreamAllocator.H"
+#include "OSstream.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// Forward declaration
+template<class T, int SizeMin> class DynamicList;
+
+
+/*---------------------------------------------------------------------------*\
+ Class UOBufStream Declaration
+\*---------------------------------------------------------------------------*/
+
+//- An OSstream attached to an unallocated external buffer
+class UOBufStream
+:
+ public BufStreamAllocator<std::ostream,false>,
+ public OSstream
+{
+ typedef BufStreamAllocator<std::ostream,false> allocator_type;
+
+public:
+
+ // Constructors
+
+ //- Construct using specified buffer and number of bytes
+ UOBufStream
+ (
+ char* buffer,
+ size_t nbytes,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion
+ )
+ :
+ allocator_type(buffer, nbytes),
+ OSstream(stream_, "output", format,version)
+ {}
+
+
+ //- Construct using data area from a List and number of bytes
+ UOBufStream
+ (
+ UList<char>& buffer,
+ size_t size,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion
+ )
+ :
+ UOBufStream(buffer.data(), size, format,version)
+ {}
+
+
+ //- Construct using data area from a List and its inherent storage size
+ UOBufStream
+ (
+ UList<char>& buffer,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion
+ )
+ :
+ UOBufStream(buffer.data(), buffer.size(), format,version)
+ {}
+
+
+ //- Construct using data area from a DynamicList and its capacity
+ template<int SizeMin>
+ UOBufStream
+ (
+ DynamicList<char,SizeMin>& buffer,
+ streamFormat format=ASCII,
+ versionNumber version=currentVersion
+ )
+ :
+ UOBufStream(buffer.data(), buffer.capacity(), format,version)
+ {}
+
+
+ //- Destructor
+ ~UOBufStream()
+ {}
+
+
+ // Member functions
+
+ //- Return the current output position in the buffer
+ std::streampos size() const
+ {
+ return allocator_type::tellp();
+ }
+
+
+ //- Rewind the stream, clearing any old errors
+ void rewind()
+ {
+ allocator_type::rewind();
+ setGood(); // resynchronize with internal state
+ }
+
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
--
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