* Made torrent::Piece part of the api.

* Made libtorrent locale agnostic.


git-svn-id: svn://rakshasa.no/libtorrent/trunk/rtorrent@664 e378c898-3ddf-0310-93e7-cc216c733640

rak/partial_queue.h

@@ -0,0 +1,198 @@
+// rak - Rakshasa's toolbox
+// Copyright (C) 2005-2006, Jari Sundell
+//
+// 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; either version 2 of the License, or
+// (at your option) any later version.
+// 
+// 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, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+// In addition, as a special exception, the copyright holders give
+// permission to link the code of portions of this program with the
+// OpenSSL library under certain conditions as described in each
+// individual source file, and distribute linked combinations
+// including the two.
+//
+// You must obey the GNU General Public License in all respects for
+// all of the code used other than OpenSSL.  If you modify file(s)
+// with this exception, you may extend this exception to your version
+// of the file(s), but you are not obligated to do so.  If you do not
+// wish to do so, delete this exception statement from your version.
+// If you delete this exception statement from all source files in the
+// program, then also delete it here.
+//
+// Contact:  Jari Sundell <jaris@ifi.uio.no>
+//
+//           Skomakerveien 33
+//           3185 Skoppum, NORWAY
+
+#ifndef RAK_PARTIAL_QUEUE_H
+#define RAK_PARTIAL_QUEUE_H
+
+#include <cstring>
+#include <stdexcept>
+#include <inttypes.h>
+
+namespace rak {
+
+// First step, don't allow overflowing to the next layer. Only disable
+// the above layers for now.
+
+// We also include 0 in a single layer as some chunk may be available
+// only through seeders.
+
+class partial_queue {
+public:
+  typedef uint8_t                         key_type;
+  typedef uint32_t                        mapped_type;
+  typedef uint16_t                        size_type;
+  typedef std::pair<size_type, size_type> size_pair_type;
+
+  static const size_type num_layers = 8;
+
+  partial_queue() : m_data(NULL), m_maxLayerSize(0) {}
+  ~partial_queue() { disable(); }
+
+  bool                is_full() const                         { return m_ceiling == 0; }
+  bool                is_layer_full(size_type l) const        { return m_layers[l].second >= m_maxLayerSize; }
+
+  bool                is_enabled() const                      { return m_data != NULL; }
+
+  // Add check to see if we can add more. Also make it possible to
+  // check how full we are in the lower parts so the caller knows when
+  // he can stop searching.
+  //
+  // Though propably not needed, as we must continue til the first
+  // layer is full.
+
+  size_type           max_size() const                        { return m_maxLayerSize * num_layers; }
+  size_type           max_layer_size() const                  { return m_maxLayerSize; }
+
+  // Must be less that or equal to (max size_type) / num_layers.
+  void                enable(size_type ls);
+  void                disable();
+
+  void                clear();
+
+  // Safe to call while pop'ing and it will not reuse pop'ed indices
+  // so it is guaranteed to reach max_size at some point. This will
+  // ensure that the user needs to refill with new data at regular
+  // intervals.
+  bool                insert(key_type key, mapped_type value);
+
+  // Only call this when pop'ing as it moves the index.
+  bool                prepare_pop();
+
+  mapped_type         pop();
+
+private:
+  partial_queue(const partial_queue&);
+  void operator = (const partial_queue&);
+
+  static size_type    ceiling(size_type layer)                { return (2 << layer) - 1; }
+
+  void                find_non_empty();
+
+  mapped_type*        m_data;
+  size_type           m_maxLayerSize;
+
+  size_type           m_index;
+  size_type           m_ceiling;
+
+  size_pair_type      m_layers[num_layers];
+};
+
+inline void
+partial_queue::enable(size_type ls) {
+  if (ls == 0)
+    throw std::logic_error("partial_queue::enable(...) ls == 0.");
+
+  delete [] m_data;
+  m_data = new mapped_type[ls * num_layers];
+
+  m_maxLayerSize = ls;
+}
+
+inline void
+partial_queue::disable() {
+  delete [] m_data;
+  m_data = NULL;
+
+  m_maxLayerSize = 0;
+}
+
+inline void
+partial_queue::clear() {
+  if (m_data == NULL)
+    return;
+
+  m_index = 0;
+  m_ceiling = ceiling(num_layers - 1);
+
+  std::memset(m_layers, 0, num_layers * sizeof(size_pair_type));
+}
+
+inline bool
+partial_queue::insert(key_type key, mapped_type value) {
+  if (key >= m_ceiling)
+    return false;
+
+  size_type idx = 0;
+
+  // Hmm... since we already check the 'm_ceiling' above, we only need
+  // to find the target layer. Could this be calculated directly?
+  while (key >= ceiling(idx))
+    ++idx;
+
+  m_index = std::min(m_index, idx);
+
+  // Currently don't allow overflow.
+  if (is_layer_full(idx))
+    throw std::logic_error("partial_queue::insert(...) layer already full.");
+    //return false;
+
+  m_data[m_maxLayerSize * idx + m_layers[idx].second] = value;
+  m_layers[idx].second++;
+
+  if (is_layer_full(idx))
+    // Set the ceiling to 0 when layer 0 is full so no more values can
+    // be inserted.
+    m_ceiling = idx > 0 ? ceiling(idx - 1) : 0;
+
+  return true;
+}
+
+// is_empty() will iterate to the first layer with un-popped elements
+// and return true, else return false when it reaches a overflowed or
+// the last layer.
+inline bool
+partial_queue::prepare_pop() {
+  while (m_layers[m_index].first == m_layers[m_index].second) {
+    if (is_layer_full(m_index) || m_index + 1 == num_layers)
+      return false;
+
+    m_index++;
+  }
+
+  return true;
+}
+
+inline partial_queue::mapped_type
+partial_queue::pop() {
+  if (m_index >= num_layers || m_layers[m_index].first >= m_layers[m_index].second)
+    throw std::logic_error("partial_queue::pop() bad state.");
+
+  return m_data[m_index * m_maxLayerSize + m_layers[m_index].first++];
+}
+
+}
+
+#endif