1 files changed, 479 insertions, 0 deletions

diff --git a/contrib/iostream3/zfstream.cc b/contrib/iostream3/zfstream.cc
new file mode 100644
index 0000000..24d15fa
--- /dev/null
+++ b/contrib/iostream3/zfstream.cc
@@ -0,0 +1,479 @@
+/*
+ * A C++ I/O streams interface to the zlib gz* functions
+ * 
+ * by Ludwig Schwardt <schwardt@sun.ac.za>
+ * original version by Kevin Ruland <kevin@rodin.wustl.edu>
+ * 
+ * This version is standard-compliant and compatible with gcc 3.x.
+ */
+
+#include "zfstream.h"
+#include <cstring>          // for strcpy, strcat, strlen (mode strings)
+#include <cstdio>           // for BUFSIZ
+
+// Internal buffer sizes (default and "unbuffered" versions)
+#define BIGBUFSIZE BUFSIZ
+#define SMALLBUFSIZE 1
+
+/*****************************************************************************/
+
+// Default constructor
+gzfilebuf::gzfilebuf() 
+: file(NULL), io_mode(std::ios_base::openmode(0)), own_fd(false), 
+  buffer(NULL), buffer_size(BIGBUFSIZE), own_buffer(true)
+{
+  // No buffers to start with
+  this->disable_buffer();
+}
+
+// Destructor
+gzfilebuf::~gzfilebuf() 
+{
+  // Sync output buffer and close only if responsible for file
+  // (i.e. attached streams should be left open at this stage)
+  this->sync();
+  if (own_fd) 
+    this->close();
+  // Make sure internal buffer is deallocated
+  this->disable_buffer();
+}
+
+// Set compression level and strategy
+int
+gzfilebuf::setcompression(int comp_level,
+                          int comp_strategy)
+{
+  return gzsetparams(file, comp_level, comp_strategy);
+}
+
+// Open gzipped file
+gzfilebuf* 
+gzfilebuf::open(const char *name, 
+                std::ios_base::openmode mode)
+{
+  // Fail if file already open
+  if (this->is_open()) 
+    return NULL;
+  // Don't support simultaneous read/write access (yet)
+  if ((mode & std::ios_base::in) && (mode & std::ios_base::out)) 
+    return NULL;
+  
+  // Build mode string for gzopen and check it [27.8.1.3.2]
+  char char_mode[6] = "\0\0\0\0\0";
+  if (!this->open_mode(mode, char_mode))
+    return NULL;
+  
+  // Attempt to open file
+  if ((file = gzopen(name, char_mode)) == NULL) 
+    return NULL;
+
+  // On success, allocate internal buffer and set flags
+  this->enable_buffer();
+  io_mode = mode;
+  own_fd = true;
+  return this;
+}
+
+// Attach to gzipped file
+gzfilebuf*
+gzfilebuf::attach(int fd,
+                  std::ios_base::openmode mode) 
+{
+  // Fail if file already open
+  if (this->is_open()) 
+    return NULL;
+  // Don't support simultaneous read/write access (yet)
+  if ((mode & std::ios_base::in) && (mode & std::ios_base::out)) 
+    return NULL;
+  
+  // Build mode string for gzdopen and check it [27.8.1.3.2]
+  char char_mode[6] = "\0\0\0\0\0";
+  if (!this->open_mode(mode, char_mode))
+    return NULL;
+  
+  // Attempt to attach to file
+  if ((file = gzdopen(fd, char_mode)) == NULL)
+    return NULL;
+  
+  // On success, allocate internal buffer and set flags
+  this->enable_buffer();
+  io_mode = mode;
+  own_fd = false;
+  return this;
+}
+
+// Close gzipped file
+gzfilebuf*
+gzfilebuf::close() 
+{
+  // Fail immediately if no file is open
+  if (!this->is_open())
+    return NULL;
+  // Assume success
+  gzfilebuf* retval = this;
+  // Attempt to sync and close gzipped file
+  if (this->sync() == -1)
+    retval = NULL;
+  if (gzclose(file) < 0)
+    retval = NULL;
+  // File is now gone anyway (postcondition [27.8.1.3.8])
+  file = NULL;
+  own_fd = false;
+  // Destroy internal buffer if it exists
+  this->disable_buffer();
+  return retval;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+// Convert int open mode to mode string
+bool 
+gzfilebuf::open_mode(std::ios_base::openmode mode, 
+                     char* c_mode) const
+{
+  bool testb = mode & std::ios_base::binary;
+  bool testi = mode & std::ios_base::in;
+  bool testo = mode & std::ios_base::out;
+  bool testt = mode & std::ios_base::trunc;
+  bool testa = mode & std::ios_base::app;
+      
+  // Check for valid flag combinations - see [27.8.1.3.2] (Table 92)
+  // Original zfstream hardcoded the compression level to maximum here...
+  // Double the time for less than 1% size improvement seems
+  // excessive though - keeping it at the default level
+  // To change back, just append "9" to the next three mode strings
+  if (!testi && testo && !testt && !testa)
+    strcpy(c_mode, "w");
+  if (!testi && testo && !testt && testa)
+    strcpy(c_mode, "a");
+  if (!testi && testo && testt && !testa)
+    strcpy(c_mode, "w");
+  if (testi && !testo && !testt && !testa)
+    strcpy(c_mode, "r");
+  // No read/write mode yet
+//  if (testi && testo && !testt && !testa)
+//    strcpy(c_mode, "r+");
+//  if (testi && testo && testt && !testa)
+//    strcpy(c_mode, "w+");
+
+  // Mode string should be empty for invalid combination of flags    
+  if (strlen(c_mode) == 0)
+    return false;
+  if (testb)
+    strcat(c_mode, "b");
+  return true;
+}
+
+// Determine number of characters in internal get buffer
+std::streamsize 
+gzfilebuf::showmanyc()
+{
+  // Calls to underflow will fail if file not opened for reading
+  if (!this->is_open() || !(io_mode & std::ios_base::in))
+    return -1;
+  // Make sure get area is in use
+  if (this->gptr() && (this->gptr() < this->egptr()))
+    return std::streamsize(this->egptr() - this->gptr());
+  else
+    return 0;
+}
+
+// Fill get area from gzipped file
+gzfilebuf::int_type
+gzfilebuf::underflow() 
+{
+  // If something is left in the get area by chance, return it
+  // (this shouldn't normally happen, as underflow is only supposed 
+  // to be called when gptr >= egptr, but it serves as error check)
+  if (this->gptr() && (this->gptr() < this->egptr()))
+    return traits_type::to_int_type(*(this->gptr()));
+
+  // If the file hasn't been opened for reading, produce error
+  if (!this->is_open() || !(io_mode & std::ios_base::in))
+    return traits_type::eof();
+
+  // Attempt to fill internal buffer from gzipped file
+  // (buffer must be guaranteed to exist...)
+  int bytes_read = gzread(file, buffer, buffer_size);
+  // Indicates error or EOF
+  if (bytes_read <= 0)
+  {
+    // Reset get area
+    this->setg(buffer, buffer, buffer);
+    return traits_type::eof();
+  }
+  // Make all bytes read from file available as get area
+  this->setg(buffer, buffer, buffer + bytes_read);
+  
+  // Return next character in get area
+  return traits_type::to_int_type(*(this->gptr()));
+}
+
+// Write put area to gzipped file
+gzfilebuf::int_type
+gzfilebuf::overflow(int_type c) 
+{
+  // Determine whether put area is in use
+  if (this->pbase())
+  {
+    // Double-check pointer range
+    if (this->pptr() > this->epptr() || this->pptr() < this->pbase())
+      return traits_type::eof();
+    // Add extra character to buffer if not EOF
+    if (!traits_type::eq_int_type(c, traits_type::eof()))
+    {
+      *(this->pptr()) = traits_type::to_char_type(c);
+      this->pbump(1);
+    }
+    // Number of characters to write to file
+    int bytes_to_write = this->pptr() - this->pbase();
+    // Overflow doesn't fail if nothing is to be written
+    if (bytes_to_write > 0)
+    {
+      // If the file hasn't been opened for writing, produce error
+      if (!this->is_open() || !(io_mode & std::ios_base::out))
+        return traits_type::eof();
+      // If gzipped file won't accept all bytes written to it, fail
+      if (gzwrite(file, this->pbase(), bytes_to_write) != bytes_to_write)
+        return traits_type::eof();
+      // Reset next pointer to point to pbase on success
+      this->pbump(-bytes_to_write);
+    }
+  }
+  // Write extra character to file if not EOF
+  else if (!traits_type::eq_int_type(c, traits_type::eof()))
+  {
+    // If the file hasn't been opened for writing, produce error
+    if (!this->is_open() || !(io_mode & std::ios_base::out))
+      return traits_type::eof();
+    // Impromptu char buffer (allows "unbuffered" output)
+    char_type last_char = traits_type::to_char_type(c);
+    // If gzipped file won't accept this character, fail
+    if (gzwrite(file, &last_char, 1) != 1)
+      return traits_type::eof();      
+  }
+
+  // If you got here, you have succeeded (even if c was EOF)
+  // The return value should therefore be non-EOF
+  if (traits_type::eq_int_type(c, traits_type::eof()))
+    return traits_type::not_eof(c);
+  else
+    return c;
+}
+
+// Assign new buffer
+std::streambuf* 
+gzfilebuf::setbuf(char_type* p,
+                  std::streamsize n)
+{
+  // First make sure stuff is sync'ed, for safety
+  if (this->sync() == -1)
+    return NULL;
+  // If buffering is turned off on purpose via setbuf(0,0), still allocate one...
+  // "Unbuffered" only really refers to put [27.8.1.4.10], while get needs at
+  // least a buffer of size 1 (very inefficient though, therefore make it bigger?)
+  // This follows from [27.5.2.4.3]/12 (gptr needs to point at something, it seems)
+  if (!p || !n)
+  {
+    // Replace existing buffer (if any) with small internal buffer
+    this->disable_buffer();
+    buffer = NULL;
+    buffer_size = 0;
+    own_buffer = true;
+    this->enable_buffer();
+  }
+  else
+  {
+    // Replace existing buffer (if any) with external buffer
+    this->disable_buffer();
+    buffer = p;
+    buffer_size = n;
+    own_buffer = false;
+    this->enable_buffer();
+  }
+  return this;
+}
+
+// Write put area to gzipped file (i.e. ensures that put area is empty)
+int 
+gzfilebuf::sync() 
+{
+  return traits_type::eq_int_type(this->overflow(), traits_type::eof()) ? -1 : 0;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+// Allocate internal buffer
+void 
+gzfilebuf::enable_buffer() 
+{
+  // If internal buffer required, allocate one
+  if (own_buffer && !buffer) 
+  {
+    // Check for buffered vs. "unbuffered"
+    if (buffer_size > 0)
+    {
+      // Allocate internal buffer
+      buffer = new char_type[buffer_size];
+      // Get area starts empty and will be expanded by underflow as need arises
+      this->setg(buffer, buffer, buffer);
+      // Setup entire internal buffer as put area.
+      // The one-past-end pointer actually points to the last element of the buffer,
+      // so that overflow(c) can safely add the extra character c to the sequence.
+      // These pointers remain in place for the duration of the buffer
+      this->setp(buffer, buffer + buffer_size - 1);
+    }
+    else
+    {
+      // Even in "unbuffered" case, (small?) get buffer is still required
+      buffer_size = SMALLBUFSIZE;
+      buffer = new char_type[buffer_size];
+      this->setg(buffer, buffer, buffer);
+      // "Unbuffered" means no put buffer
+      this->setp(0, 0);
+    }
+  }
+  else
+  {
+    // If buffer already allocated, reset buffer pointers just to make sure no 
+    // stale chars are lying around
+    this->setg(buffer, buffer, buffer);
+    this->setp(buffer, buffer + buffer_size - 1);
+  }  
+}
+
+// Destroy internal buffer
+void 
+gzfilebuf::disable_buffer() 
+{
+  // If internal buffer exists, deallocate it
+  if (own_buffer && buffer)
+  {
+    // Preserve unbuffered status by zeroing size
+    if (!this->pbase())
+      buffer_size = 0;
+    delete[] buffer;
+    buffer = NULL;
+    this->setg(0, 0, 0);
+    this->setp(0, 0);
+  }
+  else
+  {
+    // Reset buffer pointers to initial state if external buffer exists
+    this->setg(buffer, buffer, buffer);
+    if (buffer)
+      this->setp(buffer, buffer + buffer_size - 1);
+    else
+      this->setp(0, 0);
+  }
+}
+
+/*****************************************************************************/
+
+// Default constructor initializes stream buffer
+gzifstream::gzifstream() 
+: std::istream(NULL), sb()
+{ this->init(&sb); }
+
+// Initialize stream buffer and open file
+gzifstream::gzifstream(const char* name,
+                       std::ios_base::openmode mode)
+: std::istream(NULL), sb()
+{
+  this->init(&sb);
+  this->open(name, mode);
+}
+
+// Initialize stream buffer and attach to file
+gzifstream::gzifstream(int fd,
+                       std::ios_base::openmode mode)
+: std::istream(NULL), sb()
+{
+  this->init(&sb);
+  this->attach(fd, mode);
+}
+
+// Open file and go into fail() state if unsuccessful
+void 
+gzifstream::open(const char* name, 
+                 std::ios_base::openmode mode)
+{
+  if (!sb.open(name, mode | std::ios_base::in))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Attach to file and go into fail() state if unsuccessful
+void 
+gzifstream::attach(int fd, 
+                   std::ios_base::openmode mode)
+{
+  if (!sb.attach(fd, mode | std::ios_base::in))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Close file
+void 
+gzifstream::close()
+{
+  if (!sb.close())
+    this->setstate(std::ios_base::failbit);
+}
+
+/*****************************************************************************/
+
+// Default constructor initializes stream buffer
+gzofstream::gzofstream() 
+: std::ostream(NULL), sb()
+{ this->init(&sb); }
+
+// Initialize stream buffer and open file
+gzofstream::gzofstream(const char* name,
+                       std::ios_base::openmode mode)
+: std::ostream(NULL), sb()
+{
+  this->init(&sb);
+  this->open(name, mode);
+}
+
+// Initialize stream buffer and attach to file
+gzofstream::gzofstream(int fd,
+                       std::ios_base::openmode mode)
+: std::ostream(NULL), sb()
+{
+  this->init(&sb);
+  this->attach(fd, mode);
+}
+
+// Open file and go into fail() state if unsuccessful
+void 
+gzofstream::open(const char* name, 
+                 std::ios_base::openmode mode)
+{
+  if (!sb.open(name, mode | std::ios_base::out))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Attach to file and go into fail() state if unsuccessful
+void 
+gzofstream::attach(int fd, 
+                   std::ios_base::openmode mode)
+{
+  if (!sb.attach(fd, mode | std::ios_base::out))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Close file
+void 
+gzofstream::close()
+{
+  if (!sb.close())
+    this->setstate(std::ios_base::failbit);
+}