Merge branch 'master' of git://github.com/korslund/mangle

stream/clients/io_stream.cpp

@@ -0,0 +1,221 @@
+#include "io_stream.hpp"
+
+// This seems to work
+#ifndef EOF
+#define EOF -1
+#endif
+
+using namespace Mangle::Stream;
+
+#define BSIZE 1024
+
+// Streambuf for normal stream reading
+class _istreambuf : public std::streambuf
+{
+  StreamPtr client;
+  char buf[BSIZE];
+
+public:
+  _istreambuf(StreamPtr strm) : client(strm)
+  {
+    // Make sure we picked the right class
+    assert(client->isReadable);
+    assert(!client->hasPtr);
+
+    // Tell streambuf to delegate reading operations to underflow()
+    setg(NULL,NULL,NULL);
+
+    // Disallow writing
+    setp(NULL,NULL);
+  }
+
+  /* Underflow is called when there is no more info to read in the
+     input buffer. We need to refill buf with new data (if any), and
+     set up the internal pointers with setg() to reflect the new
+     state.
+  */
+  int underflow()
+  {
+    // Read some more data
+    size_t read = client->read(buf, BSIZE);
+    assert(read <= BSIZE);
+
+    // If we're out of data, then EOF
+    if(read == 0)
+      return EOF;
+
+    // Otherwise, set up input buffer
+    setg(buf, buf, buf+read);
+
+    // Return the first char
+    return *((unsigned char*)buf);
+  }
+
+  // Seek stream, if the source supports it. Ignores the second
+  // parameter as Mangle doesn't separate input and output pointers.
+  std::streampos seekpos(std::streampos pos, std::ios_base::openmode = std::ios_base::in)
+  {
+    // Does this stream know how to seek?
+    if(!client->isSeekable || !client->hasPosition)
+      // If not, signal an error.
+      return -1;
+
+    // Set stream position and reset the buffer.
+    client->seek(pos);
+    setg(NULL,NULL,NULL);
+
+    return client->tell();
+  }
+};
+
+// Streambuf optimized for pointer-based input streams
+class _ptrstreambuf : public std::streambuf
+{
+  StreamPtr client;
+
+public:
+  _ptrstreambuf(StreamPtr strm) : client(strm)
+  {
+    // Make sure we picked the right class
+    assert(client->isReadable);
+    assert(client->hasPtr);
+
+    // seekpos() does all the work
+    seekpos(0);
+  }
+
+  // Underflow is only called when we're at the end of the file
+  int underflow() { return EOF; }
+
+  // Seek to a new position within the memory stream. This bypasses
+  // client->seek() entirely so isSeekable doesn't have to be set.
+  std::streampos seekpos(std::streampos pos, std::ios_base::openmode = std::ios_base::in)
+  {
+    // All pointer streams need a size
+    assert(client->hasSize);
+
+    // Figure out how much will be left of the stream after seeking
+    size_t size = client->size() - pos;
+
+    // Get a pointer
+    char* ptr = (char*)client->getPtr(pos,size);
+
+    // And use it
+    setg(ptr,ptr,ptr+size);
+
+    return pos;
+  }
+};
+
+// Streambuf for stream writing
+class _ostreambuf : public std::streambuf
+{
+  StreamPtr client;
+  char buf[BSIZE];
+
+public:
+  _ostreambuf(StreamPtr strm) : client(strm)
+  {
+    // Make sure we picked the right class
+    assert(client->isWritable);
+
+    // Inform streambuf about our nice buffer
+    setp(buf, buf+BSIZE);
+
+    // Disallow reading
+    setg(NULL,NULL,NULL);
+  }
+
+  /* Sync means to flush (write) all current data to the output
+     stream. It will also set up the entire output buffer to be usable
+     again.
+  */
+  int sync()
+  {
+    // Get the number of bytes that streambuf wants us to write
+    int num = pptr() - pbase();
+    assert(num >= 0);
+
+    // Is there any work to do?
+    if(num == 0) return 0;
+
+    if((int)client->write(pbase(), num) != num)
+      // Inform caller that writing failed
+      return -1;
+
+    // Reset output buffer pointers
+    setp(buf, buf+BSIZE);
+
+    // No error
+    return 0;
+  }
+
+  /* Called whenever the output buffer is full.
+   */
+  int overflow(int c)
+  {
+    // First, write all existing data
+    if(sync()) return EOF;
+
+    // Put the requested character in the next round of output
+    if(c != EOF)
+      {
+        *pptr() = c;
+        pbump(1);
+      }
+
+    // No error
+    return 0;
+  }
+
+  // Seek stream, if the source supports it.
+  std::streampos seekpos(std::streampos pos, std::ios_base::openmode = std::ios_base::out)
+  {
+    if(!client->isSeekable || !client->hasPosition)
+      return -1;
+
+    // Flush data and reset buffers
+    sync();
+
+    // Set stream position
+    client->seek(pos);
+
+    return client->tell();
+  }
+};
+
+MangleIStream::MangleIStream(StreamPtr inp)
+  : std::istream(NULL)
+{
+  assert(inp->isReadable);
+
+  // Pick the right streambuf implementation based on whether the
+  // input supports pointers or not.
+  if(inp->hasPtr)
+    buf = new _ptrstreambuf(inp);
+  else
+    buf = new _istreambuf(inp);
+
+  rdbuf(buf);
+}
+
+MangleIStream::~MangleIStream()
+{
+  delete buf;
+}
+
+MangleOStream::MangleOStream(StreamPtr out)
+  : std::ostream(NULL)
+{
+  assert(out->isWritable);
+  buf = new _ostreambuf(out);
+
+  rdbuf(buf);
+}
+
+MangleOStream::~MangleOStream()
+{
+  // Make sure we don't have lingering data on exit
+  flush();
+  delete buf;
+}

stream/clients/io_stream.hpp

@@ -0,0 +1,43 @@
+#ifndef MANGLE_STREAM_IOSTREAM_H
+#define MANGLE_STREAM_IOSTREAM_H
+
+#include <assert.h>
+#include "../stream.hpp"
+#include <iostream>
+
+namespace Mangle {
+namespace Stream {
+
+  /** This file contains classes for wrapping an std::istream or
+      std::ostream around a Mangle::Stream.
+
+      This allows you to use Mangle streams in places that require std
+      streams.
+
+      This is much easier than trying to make your own custom streams
+      into iostreams. The std::iostream interface is horrible and NOT
+      designed for easy subclassing. Create a Mangle::Stream instead,
+      and use this wrapper.
+  */
+
+  // An istream wrapping a readable Mangle::Stream. Has extra
+  // optimizations for pointer-based streams.
+  class MangleIStream : public std::istream
+  {
+    std::streambuf *buf;
+  public:
+    MangleIStream(StreamPtr inp);
+    ~MangleIStream();
+  };
+
+  // An ostream wrapping a writable Mangle::Stream.
+  class MangleOStream : public std::ostream
+  {
+    std::streambuf *buf;
+  public:
+    MangleOStream(StreamPtr inp);
+    ~MangleOStream();
+  };
+
+}} // namespaces
+#endif

stream/servers/std_ostream.hpp

@@ -25,11 +25,7 @@ class StdOStream : public Stream
     hasPosition = true;
     hasSize = true;
     isWritable = true;
-  }
+    isReadable = false;
-
-  size_t read(void*,size_t)
-  {
-    assert(0&&"reading not supported by StdOStream");
   }
 
   size_t write(const void* buf, size_t len)

stream/stream.hpp

@@ -24,28 +24,38 @@ class Stream
   bool hasSize;
 
   /// If true, write() works. Writing through pointer operations is
-  /// not supported.
+  /// not (yet) supported.
   bool isWritable;
 
+  /// If true, read() and eof() works.
+  bool isReadable;
+
   /// If true, the getPtr() functions work
   bool hasPtr;
 
-  /// Initialize all bools to false by default
+  /// Initialize all bools to false by default, except isReadable.
   Stream() :
     isSeekable(false), hasPosition(false), hasSize(false),
-    isWritable(false), hasPtr(false) {}
+    isWritable(false), isReadable(true), hasPtr(false) {}
 
   /// Virtual destructor
   virtual ~Stream() {}
 
   /** Read a given number of bytes from the stream. Returns the actual
       number read. If the return value is less than count, then the
-      stream is empty or an error occured.
+      stream is empty or an error occured. Only required for readable
+      streams.
   */
-  virtual size_t read(void* buf, size_t count) = 0;
+  virtual size_t read(void* buf, size_t count) { assert(0); return 0; }
 
   /** Write a given number of bytes from the stream. Semantics is
-      similar to read(). Only valid if isWritable is true
+      similar to read(). Only valid if isWritable is true.
+
+      The returned value is the number of bytes written. However in
+      most cases, unlike for read(), a write-count less than requested
+      usually indicates an error. The implementation should throw such
+      errors as exceptions rather than expect the caller to handle
+      them.
 
       Since most implementations do NOT support writing we default to
       an assert(0) here.
@@ -57,18 +67,20 @@ class Stream
 
   /// Seek to an absolute position in this stream. Not all streams are
   /// seekable.
-  virtual void seek(size_t pos) = 0;
+  virtual void seek(size_t pos) { assert(0); }
 
   /// Get the current position in the stream. Non-seekable streams are
   /// not required to keep track of this.
-  virtual size_t tell() const = 0;
+  virtual size_t tell() const { assert(0); return 0; }
 
-  /// Return the total size of the stream. For streams where this is
+  /// Return the total size of the stream. For streams hasSize is
-  /// not applicable, size() should return zero.
+  /// false, size() should fail in some way, since it is an error to
-  virtual size_t size() const = 0;
+  /// call it in those cases.
+  virtual size_t size() const { assert(0); return 0; }
 
-  /// Returns true if the stream is empty
+  /// Returns true if the stream is empty. Required for readable
-  virtual bool eof() const = 0;
+  /// streams.
+  virtual bool eof() const { assert(0); return 0; }
 
   /// Return a pointer to the entire stream. This function (and the
   /// other getPtr() variants below) should only be implemented for

stream/tests/Makefile

@@ -1,6 +1,6 @@
-GCC=g++ -I../ -Wall
+GCC=g++ -I../ -Wall -Werror
 
-all: ogre_client_test audiere_client_test memory_server_test buffer_filter_test file_server_test slice_filter_test file_write_test
+all: ogre_client_test audiere_client_test memory_server_test buffer_filter_test file_server_test slice_filter_test file_write_test iostream_test
 
 I_OGRE=$(shell pkg-config --cflags OGRE)
 L_OGRE=$(shell pkg-config --libs OGRE)
@@ -12,6 +12,9 @@ ogre_client_test: ogre_client_test.cpp ../stream.hpp ../clients/ogre_datastream.
 audiere_client_test: audiere_client_test.cpp ../stream.hpp ../clients/audiere_file.hpp ../clients/audiere_file.cpp
 	$(GCC) $< -o $@ ../clients/audiere_file.cpp $(L_AUDIERE)
 
+iostream_test: iostream_test.cpp ../clients/io_stream.cpp
+	$(GCC) $^ -o $@
+
 file_server_test: file_server_test.cpp ../stream.hpp ../servers/file_stream.hpp ../servers/std_stream.hpp
 	$(GCC) $< -o $@
 

stream/tests/iostream_test.cpp

@@ -0,0 +1,176 @@
+#include <iostream>
+#include "../clients/io_stream.hpp"
+#include "../servers/memory_stream.hpp"
+
+using namespace Mangle::Stream;
+using namespace std;
+
+void test1()
+{
+  cout << "Testing ASCII reading from memory:\n";
+  StreamPtr input(new MemoryStream("hello you world you", 19));
+  MangleIStream inp(input);
+
+  string str;
+  while(!inp.eof())
+    {
+      inp >> str;
+      cout << "Got: " << str << endl;
+    }
+}
+
+class Dummy : public Stream
+{
+  int count;
+
+public:
+
+  Dummy() : count(0)
+  {
+  }
+
+  size_t read(void *ptr, size_t num)
+  {
+    char *p = (char*)ptr;
+    char *start = p;
+    for(; (count < 2560) && (p-start < (int)num); count++)
+      {
+        *p = count / 10;
+        p++;
+      }
+    return p-start;
+  }
+
+  bool eof() const { return count == 2560; }
+};
+
+void test2()
+{
+  cout << "\nTesting binary reading from non-memory:\n";
+
+  StreamPtr input(new Dummy);
+  MangleIStream inp(input);
+
+  int x = 0;
+  while(!inp.eof())
+    {
+      unsigned char buf[5];
+      inp.read((char*)buf,5);
+
+      // istream doesn't set eof() until we read _beyond_ the end of
+      // the stream, so we need an extra check.
+      if(inp.gcount() == 0) break;
+
+      /*
+      for(int i=0;i<5;i++)
+        cout << (int)buf[i] << " ";
+      cout << endl;
+      */
+
+      assert(buf[4] == buf[0]);
+      assert(buf[0] == x/2);
+      x++;
+    }
+  cout << "  Done\n";
+}
+
+struct Dummy2 : Stream
+{
+  Dummy2() 
+  {
+    isWritable = true;
+    isReadable = false;
+  }
+
+  size_t write(const void *ptr, size_t num)
+  {
+    const char *p = (const char*)ptr;
+    cout << "    Got: ";
+    for(unsigned i=0;i<num;i++)
+      cout << *(p++) << " ";
+    cout << endl;
+    return num;
+  }
+};
+
+void test3()
+{
+  cout << "\nWriting to dummy stream:\n";
+
+  cout << "  Pure dummy test:\n";
+  StreamPtr output(new Dummy2);
+  output->write("testing", 7);
+
+  cout << "  Running through MangleOStream:\n";
+  MangleOStream out(output);
+  out << "hello";
+  out << " - are you ok?";
+  cout << "  Flushing:\n";
+  out.flush();
+
+  cout << "  Writing a hell of a lot of characters:\n";
+  for(int i=0; i<127; i++)
+    out << "xxxxxxxx"; // 127 * 8 = 1016
+  out << "fffffff"; // +7 = 1023
+  cout << "  Just one more:\n";
+  out << "y";
+  cout << "  And oooone more:\n";
+  out << "z";
+
+  cout << "  Flushing again:\n";
+  out.flush();
+  cout << "  Writing some more and exiting:\n";
+  out << "blah bleh blob";
+}
+
+struct Dummy3 : Stream
+{
+  int pos;
+
+  Dummy3() : pos(0)
+  {
+    hasPosition = true;
+    isSeekable = true;
+  }
+
+  size_t read(void*, size_t num)
+  {
+    cout << "    Reading " << num << " bytes from " << pos << endl;
+    pos += num;
+    return num;
+  }
+
+  void seek(size_t npos) { pos = npos; }
+  size_t tell() const { return pos; }
+};
+
+void test4()
+{
+  cout << "\nTesting seeking;\n";
+  StreamPtr input(new Dummy3);
+
+  cout << "  Direct reading:\n";
+  input->read(0,10);
+  input->read(0,5);
+
+  MangleIStream inp(input);
+
+  cout << "  Reading from istream:\n";
+  char buf[20];
+  inp.read(buf, 20);
+  inp.read(buf, 20);
+  inp.read(buf, 20);
+
+  cout << "  Seeking to 30 and reading again:\n";
+  inp.seekg(30);
+  inp.read(buf, 20);
+}
+
+int main()
+{
+  test1();
+  test2();
+  test3();
+  test4();
+  return 0;
+}

stream/tests/output/iostream_test.out

@@ -0,0 +1,32 @@
+Testing ASCII reading from memory:
+Got: hello
+Got: you
+Got: world
+Got: you
+
+Testing binary reading from non-memory:
+  Done
+
+Writing to dummy stream:
+  Pure dummy test:
+    Got: t e s t i n g 
+  Running through MangleOStream:
+  Flushing:
+    Got: h e l l o   -   a r e   y o u   o k ? 
+  Writing a hell of a lot of characters:
+  Just one more:
+  And oooone more:
+    Got: x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x f f f f f f f y 
+  Flushing again:
+    Got: z 
+  Writing some more and exiting:
+    Got: b l a h   b l e h   b l o b 
+
+Testing seeking;
+  Direct reading:
+    Reading 10 bytes from 0
+    Reading 5 bytes from 10
+  Reading from istream:
+    Reading 1024 bytes from 15
+  Seeking to 30 and reading again:
+    Reading 1024 bytes from 30