Add base64 encoding layer (issue #272)

- Can be attached to any currently open std::ostream.

applications/test/base64/Make/files

@@ -0,0 +1,3 @@
+Test-base64Encoding.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-base64Encoding

applications/test/base64/Test-base64Encoding.C

@@ -0,0 +1,169 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 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/>.
+
+Application
+    Test-base64Encoding
+
+Description
+    Test base64 encoding layer.
+
+    Target values generated with "base64 encode ..." in Google.
+    A simple independent source for comparison.
+
+\*---------------------------------------------------------------------------*/
+
+#include "base64Layer.H"
+#include "List.H"
+#include "Pair.H"
+
+#include <sstream>
+#include <initializer_list>
+
+using namespace Foam;
+
+bool test(const Pair<string>& unit)
+{
+    const string& input = unit.first();
+    const string& expected = unit.second();
+
+    std::ostringstream os;
+
+    base64Layer b64(os);
+    b64.write(input.data(), input.size());
+    b64.close();
+
+    const string encoded = os.str();
+
+    Info<< input << nl;
+
+    if (encoded == expected)
+    {
+        Info<< "  encoded: " << encoded << " (OK)" << nl
+            << endl;
+        return true;
+    }
+    else
+    {
+        Info<< "  encoded: " << encoded << " (ERROR)" << nl
+            << "  expected: " << expected << nl
+            << endl;
+
+        return false;
+    }
+}
+
+
+bool test(std::initializer_list<Pair<string>> list)
+{
+    bool good = true;
+
+    for (const Pair<string>& t : list)
+    {
+        good = test(t) && good;
+    }
+
+    return good;
+}
+
+
+bool test(const UList<Pair<string>>& list)
+{
+    bool good = true;
+
+    for (const Pair<string>& t : list)
+    {
+        good = test(t) && good;
+    }
+
+    return good;
+}
+
+
+void testMixed(std::ostream& os, const UList<Pair<string>>& list)
+{
+    base64Layer b64(os);
+
+    os  << "<test-mixed>" << nl;
+
+    int i=0;
+    for (const Pair<string>& t : list)
+    {
+        const string& input = t.first();
+
+        os  << "<input" << ++i << " value='" << input << "'>" << nl;
+        os  << "  ";
+
+        b64.write(input.data(), input.size());
+        b64.close();
+
+        os  << nl
+            << "</input" << i << ">" << nl;
+    }
+
+    os  << "</test-mixed>" << nl
+        <<  nl;
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+int main(int argc, char * argv[])
+{
+    Info<< "Test base64 encode layer" << nl << endl;
+
+    List<Pair<string>> testList
+    {
+        {
+            "abcdef",  // 6 input, 8 output
+            "YWJjZGVm"
+        },
+        {
+            "OpenFOAM",
+            "T3BlbkZPQU0="
+        },
+        {
+            "OpenFOAM: The Open Source CFD Toolbox",
+            "T3BlbkZPQU06IFRoZSBPcGVuIFNvdXJjZSBDRkQgVG9vbGJveA=="
+        }
+    };
+
+
+    bool good = test(testList);
+
+
+    // Test mixing output
+    testMixed(std::cout, testList);
+
+    if (good)
+    {
+        Info<< "All tests passed" << endl;
+        return 0;
+    }
+    else
+    {
+        Info<< "One or more tests failed" << endl;
+        return 1;
+    }
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

src/OpenFOAM/Make/files

@@ -144,6 +144,9 @@ $(Sstreams)/SstreamsPrint.C
 $(Sstreams)/readHexLabel.C
 $(Sstreams)/prefixOSstream.C
 
+hashes = $(Streams)/hashes
+$(hashes)/base64Layer.C
+
 gzstream = $(Streams)/gzstream
 $(gzstream)/gzstream.C
 

src/OpenFOAM/db/IOstreams/hashes/base64Layer.C

@@ -0,0 +1,168 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 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/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "base64Layer.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+//! \cond fileScope
+//- The characters used for base-64
+static const unsigned char base64Chars[64] =
+{
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+    'w', 'x', 'y', 'z', '0', '1', '2', '3',
+    '4', '5', '6', '7', '8', '9', '+', '/'
+};
+//! \endcond
+
+
+// * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
+
+inline unsigned char Foam::base64Layer::encode0()
+{
+    // Top 6 bits of char0
+    return base64Chars[((group_[0] & 0xFC) >> 2)];
+}
+
+inline unsigned char Foam::base64Layer::encode1()
+{
+    // Bottom 2 bits of char0, Top 4 bits of char1
+    return base64Chars[((group_[0] & 0x03) << 4) | ((group_[1] & 0xF0) >> 4)];
+}
+
+inline unsigned char Foam::base64Layer::encode2()
+{
+    // Bottom 4 bits of char1, Top 2 bits of char2
+    return base64Chars[((group_[1] & 0x0F) << 2) | ((group_[2] & 0xC0) >> 6)];
+}
+
+inline unsigned char Foam::base64Layer::encode3()
+{
+    // Bottom 6 bits of char2
+    return base64Chars[(group_[2] & 0x3F)];
+}
+
+
+void Foam::base64Layer::add(char c)
+{
+    group_[groupLen_++] = static_cast<unsigned char>(c);
+    if (groupLen_ == 3)
+    {
+        unsigned char out[4];
+
+        out[0] = encode0();
+        out[1] = encode1();
+        out[2] = encode2();
+        out[3] = encode3();
+        os_.write(reinterpret_cast<char*>(out), 4);
+
+        groupLen_ = 0;
+    }
+
+    dirty_ = true;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::base64Layer::base64Layer(std::ostream& os)
+:
+    os_(os),
+    group_(),
+    groupLen_(0),
+    dirty_(false)
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+Foam::base64Layer::~base64Layer()
+{
+    close();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::base64Layer::write(const char* s, std::streamsize n)
+{
+    for (std::streamsize i=0; i < n; ++i)
+    {
+        add(s[i]);
+    }
+}
+
+
+void Foam::base64Layer::reset()
+{
+    groupLen_ = 0;
+    dirty_ = false;
+}
+
+
+bool Foam::base64Layer::close()
+{
+    if (!dirty_)
+    {
+        return false;
+    }
+
+    unsigned char out[4];
+    if (groupLen_ == 1)
+    {
+        group_[1] = 0;
+
+        out[0] = encode0();
+        out[1] = encode1();
+        out[2] = '=';
+        out[3] = '=';
+        os_.write(reinterpret_cast<char*>(out), 4);
+    }
+    else if (groupLen_ == 2)
+    {
+        group_[2] = 0;
+
+        out[0] = encode0();
+        out[1] = encode1();
+        out[2] = encode2();
+        out[3] = '=';
+        os_.write(reinterpret_cast<char*>(out), 4);
+    }
+
+    // group-length == 0 (no content)
+    // group-length == 3 is not possible, already reset in add()
+
+    groupLen_ = 0;
+    dirty_ = false;
+
+    return true;
+}
+
+
+// ************************************************************************* //

src/OpenFOAM/db/IOstreams/hashes/base64Layer.H

@@ -0,0 +1,127 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 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
+    base64Layer
+
+Description
+    An output filter layer to write base-64 encoded content.
+
+    Base64 encoding accoding to RFC 4648 specification
+    (https://tools.ietf.org/html/rfc4648#page-5).
+    It is the obligation of the caller to avoid using normal output
+    while the base-64 encoding layer is actively being used.
+
+SourceFiles
+    base64Layer.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef base64Layer_H
+#define base64Layer_H
+
+#include <iostream>
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class base64Layer Declaration
+\*---------------------------------------------------------------------------*/
+
+class base64Layer
+{
+    // Private data
+
+        //- The output stream for the layer
+        std::ostream& os_;
+
+        //- Buffer of characters to encode
+        unsigned char group_[3];
+
+        //- Current length of the encode buffer
+        unsigned char groupLen_;
+
+        //- Track if anything has been encoded.
+        bool dirty_;
+
+
+    // Private Member Functions
+
+        inline unsigned char encode0();
+        inline unsigned char encode1();
+        inline unsigned char encode2();
+        inline unsigned char encode3();
+
+        //- Disallow default bitwise copy construct
+        base64Layer(const base64Layer&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const base64Layer&) = delete;
+
+
+protected:
+
+    // Protected Member Functions
+
+        //- Add a character to the group, outputting when the group is full.
+        void add(char c);
+
+
+public:
+
+    // Constructors
+
+        //- Construct and attach to an output stream
+        base64Layer(std::ostream&);
+
+
+    //- Destructor
+    ~base64Layer();
+
+
+    // Member Functions
+
+        //- Encode the character sequence, writing when possible.
+        void write(const char* s, std::streamsize n);
+
+        //- Restart a new encoding sequence.
+        void reset();
+
+        //- End the encoding sequence, padding the final characters with '='.
+        //  Return false if no encoding layer was actually used.
+        bool close();
+
+};
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //