From 19a4dad7065e771257a11e465fcb2da44b1a1df0 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 24 Jan 2004 17:14:03 +0000
Subject: [PATCH] *** empty log message ***

---
 docs/manual.html                       | 124 +++++++++++++++++--------
 docs/manual.rst                        |  38 +++++++-
 examples/client_test.cpp               |   4 +-
 include/libtorrent/alert_types.hpp     |   3 +
 include/libtorrent/hasher.hpp          |  20 ++++
 include/libtorrent/peer_connection.hpp |   1 -
 include/libtorrent/piece_picker.hpp    |   2 +-
 include/libtorrent/session.hpp         |   4 +-
 include/libtorrent/storage.hpp         |   7 ++
 src/identify_client.cpp                |   8 +-
 src/peer_connection.cpp                |  23 ++++-
 src/policy.cpp                         |  10 +-
 src/session.cpp                        |  61 ++++++++++--
 src/storage.cpp                        | 101 +++++++++++++++-----
 src/torrent_handle.cpp                 |  16 +++-
 src/torrent_info.cpp                   |  28 +++---
 16 files changed, 341 insertions(+), 109 deletions(-)

diff --git a/docs/manual.html b/docs/manual.html
index 788a9a1f1..90779cbb9 100755
--- a/docs/manual.html
+++ b/docs/manual.html
@@ -14,56 +14,59 @@
 <p class="topic-title"><a name="contents">Contents</a></p>
 <ul class="simple">
 <li><a class="reference" href="#introduction" id="id9" name="id9">introduction</a></li>
-<li><a class="reference" href="#building" id="id10" name="id10">building</a></li>
-<li><a class="reference" href="#using" id="id11" name="id11">using</a></li>
-<li><a class="reference" href="#session" id="id12" name="id12">session</a></li>
-<li><a class="reference" href="#parsing-torrent-files" id="id13" name="id13">parsing torrent files</a></li>
-<li><a class="reference" href="#entry" id="id14" name="id14">entry</a></li>
-<li><a class="reference" href="#torrent-info" id="id15" name="id15">torrent_info</a></li>
-<li><a class="reference" href="#torrent-handle" id="id16" name="id16">torrent_handle</a><ul>
-<li><a class="reference" href="#status" id="id17" name="id17">status()</a></li>
-<li><a class="reference" href="#get-download-queue" id="id18" name="id18">get_download_queue()</a></li>
-<li><a class="reference" href="#get-peer-info" id="id19" name="id19">get_peer_info()</a></li>
-<li><a class="reference" href="#get-torrent-info" id="id20" name="id20">get_torrent_info()</a></li>
-<li><a class="reference" href="#is-valid" id="id21" name="id21">is_valid()</a></li>
+<li><a class="reference" href="#building" id="id10" name="id10">building</a><ul>
+<li><a class="reference" href="#release-and-debug-builds" id="id11" name="id11">release and debug builds</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#address" id="id22" name="id22">address</a></li>
-<li><a class="reference" href="#http-settings" id="id23" name="id23">http_settings</a></li>
-<li><a class="reference" href="#big-number" id="id24" name="id24">big_number</a></li>
-<li><a class="reference" href="#hasher" id="id25" name="id25">hasher</a></li>
-<li><a class="reference" href="#fingerprint" id="id26" name="id26">fingerprint</a><ul>
-<li><a class="reference" href="#identify-client" id="id27" name="id27">identify_client</a></li>
+<li><a class="reference" href="#using" id="id12" name="id12">using</a></li>
+<li><a class="reference" href="#session" id="id13" name="id13">session</a></li>
+<li><a class="reference" href="#parsing-torrent-files" id="id14" name="id14">parsing torrent files</a></li>
+<li><a class="reference" href="#entry" id="id15" name="id15">entry</a></li>
+<li><a class="reference" href="#torrent-info" id="id16" name="id16">torrent_info</a></li>
+<li><a class="reference" href="#torrent-handle" id="id17" name="id17">torrent_handle</a><ul>
+<li><a class="reference" href="#status" id="id18" name="id18">status()</a></li>
+<li><a class="reference" href="#get-download-queue" id="id19" name="id19">get_download_queue()</a></li>
+<li><a class="reference" href="#get-peer-info" id="id20" name="id20">get_peer_info()</a></li>
+<li><a class="reference" href="#get-torrent-info" id="id21" name="id21">get_torrent_info()</a></li>
+<li><a class="reference" href="#is-valid" id="id22" name="id22">is_valid()</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#alerts" id="id28" name="id28">alerts</a><ul>
-<li><a class="reference" href="#tracker-alert" id="id29" name="id29">tracker_alert</a></li>
-<li><a class="reference" href="#hash-failed-alert" id="id30" name="id30">hash_failed_alert</a></li>
-<li><a class="reference" href="#peer-error-alert" id="id31" name="id31">peer_error_alert</a></li>
-<li><a class="reference" href="#invalid-request-alert" id="id32" name="id32">invalid_request_alert</a></li>
-<li><a class="reference" href="#torrent-finished-alert" id="id33" name="id33">torrent_finished_alert</a></li>
-<li><a class="reference" href="#dispatcher" id="id34" name="id34">dispatcher</a></li>
+<li><a class="reference" href="#address" id="id23" name="id23">address</a></li>
+<li><a class="reference" href="#http-settings" id="id24" name="id24">http_settings</a></li>
+<li><a class="reference" href="#big-number" id="id25" name="id25">big_number</a></li>
+<li><a class="reference" href="#hasher" id="id26" name="id26">hasher</a></li>
+<li><a class="reference" href="#fingerprint" id="id27" name="id27">fingerprint</a><ul>
+<li><a class="reference" href="#identify-client" id="id28" name="id28">identify_client</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#exceptions" id="id35" name="id35">exceptions</a><ul>
-<li><a class="reference" href="#invalid-handle" id="id36" name="id36">invalid_handle</a></li>
-<li><a class="reference" href="#duplicate-torrent" id="id37" name="id37">duplicate_torrent</a></li>
-<li><a class="reference" href="#invalid-encoding" id="id38" name="id38">invalid_encoding</a></li>
-<li><a class="reference" href="#type-error" id="id39" name="id39">type_error</a></li>
-<li><a class="reference" href="#invalid-torrent-file" id="id40" name="id40">invalid_torrent_file</a></li>
+<li><a class="reference" href="#alerts" id="id29" name="id29">alerts</a><ul>
+<li><a class="reference" href="#tracker-alert" id="id30" name="id30">tracker_alert</a></li>
+<li><a class="reference" href="#hash-failed-alert" id="id31" name="id31">hash_failed_alert</a></li>
+<li><a class="reference" href="#peer-error-alert" id="id32" name="id32">peer_error_alert</a></li>
+<li><a class="reference" href="#invalid-request-alert" id="id33" name="id33">invalid_request_alert</a></li>
+<li><a class="reference" href="#torrent-finished-alert" id="id34" name="id34">torrent_finished_alert</a></li>
+<li><a class="reference" href="#dispatcher" id="id35" name="id35">dispatcher</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#examples" id="id41" name="id41">examples</a><ul>
-<li><a class="reference" href="#dump-torrent" id="id42" name="id42">dump_torrent</a></li>
-<li><a class="reference" href="#simple-client" id="id43" name="id43">simple client</a></li>
+<li><a class="reference" href="#exceptions" id="id36" name="id36">exceptions</a><ul>
+<li><a class="reference" href="#invalid-handle" id="id37" name="id37">invalid_handle</a></li>
+<li><a class="reference" href="#duplicate-torrent" id="id38" name="id38">duplicate_torrent</a></li>
+<li><a class="reference" href="#invalid-encoding" id="id39" name="id39">invalid_encoding</a></li>
+<li><a class="reference" href="#type-error" id="id40" name="id40">type_error</a></li>
+<li><a class="reference" href="#invalid-torrent-file" id="id41" name="id41">invalid_torrent_file</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#fast-resume" id="id44" name="id44">fast resume</a><ul>
-<li><a class="reference" href="#file-format" id="id45" name="id45">file format</a></li>
+<li><a class="reference" href="#examples" id="id42" name="id42">examples</a><ul>
+<li><a class="reference" href="#dump-torrent" id="id43" name="id43">dump_torrent</a></li>
+<li><a class="reference" href="#simple-client" id="id44" name="id44">simple client</a></li>
 </ul>
 </li>
-<li><a class="reference" href="#extensions" id="id46" name="id46">extensions</a></li>
-<li><a class="reference" href="#aknowledgements" id="id47" name="id47">aknowledgements</a></li>
+<li><a class="reference" href="#fast-resume" id="id45" name="id45">fast resume</a><ul>
+<li><a class="reference" href="#file-format" id="id46" name="id46">file format</a></li>
+</ul>
+</li>
+<li><a class="reference" href="#extensions" id="id47" name="id47">extensions</a></li>
+<li><a class="reference" href="#aknowledgements" id="id48" name="id48">aknowledgements</a></li>
 </ul>
 </div>
 <div class="section" id="introduction">
@@ -105,6 +108,8 @@ peers in a separate fast-resume file.</li>
 <li>supports the <tt class="literal"><span class="pre">no_peer_id=1</span></tt> extension that will ease the load off trackers.</li>
 <li>supports the <a class="reference" href="udp_tracker_protocol.html">udp-tracker protocol</a>.</li>
 <li>possibility to limit the number of connections.</li>
+<li>delays have messages if there's no other outgoing traffic to the peer, and doesn't
+send have messages to peers that already has the piece. This saves bandwidth.</li>
 </ul>
 </blockquote>
 <p>Functions that are yet to be implemented:</p>
@@ -136,9 +141,6 @@ boost.filesystem, boost.date_time and various other boost libraries as well as z
 </div>
 <div class="section" id="building">
 <h1><a name="building">building</a></h1>
-<p>Whwn building in release mode you need to define NDEBUG in order to avoid
-all asserts and invariant checks within libtorrent. Developer studio does
-this by default.</p>
 <p>To build libtorrent you need <a class="reference" href="http://www.boost.org">boost</a> and bjam installed.
 Then you can use <tt class="literal"><span class="pre">bjam</span></tt> to build libtorrent.</p>
 <p>To make bjam work, you need to set the environment variable <tt class="literal"><span class="pre">BOOST_ROOT</span></tt> to the
@@ -168,6 +170,46 @@ of the file:</p>
 <p>In developer studio, you may have to set the compiler options &quot;force conformance in for
 loop scope&quot; and &quot;treat wchar_t as built-in type&quot; to Yes.</p>
 <p>TODO: more detailed build instructions.</p>
+<div class="section" id="release-and-debug-builds">
+<h2><a name="release-and-debug-builds">release and debug builds</a></h2>
+<p>If you just invoke the makefile you'll get a debug build. In debug the libtorrent vill
+have pretty expensive invariant checks and asserts built into it. If you want to disable
+such checks (you want to do that in a release build) you can see the table below for which
+defines you can use to control the build.</p>
+<table border class="table">
+<colgroup>
+<col width="39%" />
+<col width="61%" />
+</colgroup>
+<thead valign="bottom">
+<tr><th>macro</th>
+<th>description</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr><td><tt class="literal"><span class="pre">NDEBUG</span></tt></td>
+<td>If you define this macro, all asserts,
+invariant checks and general debug code will be
+removed. This option takes precedence over
+other debug settings.</td>
+</tr>
+<tr><td><tt class="literal"><span class="pre">TORRENT_VERBOSE_LOGGING</span></tt></td>
+<td>If you define this macro, every peer connection
+will log its traffic to a log file.
+This setting requires a debug build, i.e.
+if you set <tt class="literal"><span class="pre">NDEBUG</span></tt> aswell, no logs will be
+written.</td>
+</tr>
+<tr><td><tt class="literal"><span class="pre">TORRENT_STORAGE_DEBUG</span></tt></td>
+<td>This will enable extra expensive invariant
+checks in the storage, including logging of
+piece sorting.</td>
+</tr>
+</tbody>
+</table>
+<p>If you experience that libtorrent uses unreasonable amounts of cpu, it will definately help to
+define <tt class="literal"><span class="pre">NDEBUG</span></tt>.</p>
+</div>
 </div>
 <div class="section" id="using">
 <h1><a name="using">using</a></h1>
diff --git a/docs/manual.rst b/docs/manual.rst
index b32ec2d71..40f4378c4 100755
--- a/docs/manual.rst
+++ b/docs/manual.rst
@@ -42,6 +42,8 @@ The current state includes the following features:
 	* supports the ``no_peer_id=1`` extension that will ease the load off trackers.
 	* supports the `udp-tracker protocol`__.
 	* possibility to limit the number of connections.
+	* delays have messages if there's no other outgoing traffic to the peer, and doesn't
+	  send have messages to peers that already has the piece. This saves bandwidth.
 
 __ http://home.elp.rr.com/tur/multitracker-spec.txt
 .. _Azureus: http://azureus.sourceforge.net
@@ -77,11 +79,6 @@ libtorrent is released under the BSD-license_.
 building
 ========
 
-Whwn building in release mode you need to define NDEBUG in order to avoid
-all asserts and invariant checks within libtorrent. Developer studio does
-this by default.
-
-
 To build libtorrent you need boost_ and bjam installed.
 Then you can use ``bjam`` to build libtorrent.
 
@@ -122,6 +119,37 @@ loop scope" and "treat wchar_t as built-in type" to Yes.
 TODO: more detailed build instructions.
 
 
+release and debug builds
+------------------------
+
+If you just invoke the makefile you'll get a debug build. In debug the libtorrent vill
+have pretty expensive invariant checks and asserts built into it. If you want to disable
+such checks (you want to do that in a release build) you can see the table below for which
+defines you can use to control the build.
+
++-------------------------------+-------------------------------------------------+
+| macro                         | description                                     |
++===============================+=================================================+
+| ``NDEBUG``                    | If you define this macro, all asserts,          |
+|                               | invariant checks and general debug code will be |
+|                               | removed. This option takes precedence over      |
+|                               | other debug settings.                           |
++-------------------------------+-------------------------------------------------+
+| ``TORRENT_VERBOSE_LOGGING``   | If you define this macro, every peer connection |
+|                               | will log its traffic to a log file.             |
+|                               | This setting requires a debug build, i.e.       |
+|                               | if you set ``NDEBUG`` aswell, no logs will be   |
+|                               | written.                                        |
++-------------------------------+-------------------------------------------------+
+| ``TORRENT_STORAGE_DEBUG``     | This will enable extra expensive invariant      |
+|                               | checks in the storage, including logging of     |
+|                               | piece sorting.                                  |
++-------------------------------+-------------------------------------------------+
+
+
+If you experience that libtorrent uses unreasonable amounts of cpu, it will definately help to
+define ``NDEBUG``.
+
 
 
 
diff --git a/examples/client_test.cpp b/examples/client_test.cpp
index 7851418e4..6da01d645 100755
--- a/examples/client_test.cpp
+++ b/examples/client_test.cpp
@@ -400,7 +400,7 @@ int main(int argc, char* argv[])
 					}
 */
 				}
-/*
+
 				out << "___________________________________\n";
 
 				i->get_download_queue(queue);
@@ -421,7 +421,7 @@ int main(int argc, char* argv[])
 				}
 
 				out << "___________________________________\n";
-*/
+
 			}
 
 			for (std::deque<std::string>::iterator i = events.begin();
diff --git a/include/libtorrent/alert_types.hpp b/include/libtorrent/alert_types.hpp
index bafa63820..1dd2d8d3a 100755
--- a/include/libtorrent/alert_types.hpp
+++ b/include/libtorrent/alert_types.hpp
@@ -80,6 +80,7 @@ namespace libtorrent
 		virtual std::auto_ptr<alert> clone() const
 		{ return std::auto_ptr<alert>(new peer_error_alert(*this)); }
 
+		// TODO: use address instead of peer_id
 		peer_id id;
 	};
 
@@ -98,6 +99,7 @@ namespace libtorrent
 		{ return std::auto_ptr<alert>(new chat_message_alert(*this)); }
 
 		torrent_handle handle;
+		// TODO: use address instead of peer_id
 		peer_id sender;
 	};
 
@@ -118,6 +120,7 @@ namespace libtorrent
 		{ return std::auto_ptr<alert>(new invalid_request_alert(*this)); }
 
 		torrent_handle handle;
+		// TODO: use address instead of peer_id
 		peer_id sender;
 		peer_request request;
 	};
diff --git a/include/libtorrent/hasher.hpp b/include/libtorrent/hasher.hpp
index 3b10c7370..a74f56e73 100755
--- a/include/libtorrent/hasher.hpp
+++ b/include/libtorrent/hasher.hpp
@@ -41,14 +41,34 @@ extern "C"
 		unsigned char buffer[64];
 	} SHA1_CTX;
 
+	/* from sha1.c */
 	void SHA1Init(SHA1_CTX* context);
 	void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len);
 	void SHA1Final(unsigned char* digest, SHA1_CTX* context);
+
+	/* from zlib/adler32.c */
+	unsigned long adler32(unsigned long adler, const char* data, unsigned int len);
 }
 
 namespace libtorrent
 {
 
+	class adler32_crc
+	{
+	public:
+		adler32_crc(): m_adler(adler32(0, 0, 0)) {}
+
+		void update(const char* data, int len)
+		{ m_adler = adler32(m_adler, data, len); }
+		unsigned long final() const { return m_adler; }
+		void reset() { m_adler = adler32(0, 0, 0); }
+
+	private:
+
+		unsigned long m_adler;
+
+	};
+
 	class hasher
 	{
 	public:
diff --git a/include/libtorrent/peer_connection.hpp b/include/libtorrent/peer_connection.hpp
index b82e6c73c..0283e43a5 100755
--- a/include/libtorrent/peer_connection.hpp
+++ b/include/libtorrent/peer_connection.hpp
@@ -220,7 +220,6 @@ namespace libtorrent
 		void announce_piece(int index)
 		{
 			m_announce_queue.push_back(index);
-			send_buffer_updated();
 		}
 
 		// called from the main loop when this connection has any
diff --git a/include/libtorrent/piece_picker.hpp b/include/libtorrent/piece_picker.hpp
index fba4e7f14..e9a079208 100755
--- a/include/libtorrent/piece_picker.hpp
+++ b/include/libtorrent/piece_picker.hpp
@@ -92,7 +92,7 @@ namespace libtorrent
 			// info about each block
 			block_info info[max_blocks_per_piece];
 
-			// TODO: store a hash and a peer_connection reference
+			// TODO: store a crc and a peer_connection reference
 			// for each block. Then if the hash test fails on the
 			// piece, redownload one block from another peer
 			// then the first time, and check the hash again.
diff --git a/include/libtorrent/session.hpp b/include/libtorrent/session.hpp
index a4128758a..5658012cc 100755
--- a/include/libtorrent/session.hpp
+++ b/include/libtorrent/session.hpp
@@ -72,13 +72,15 @@ namespace libtorrent
 		// workaround for microsofts
 		// hardware exceptions that makes
 		// it hard to debug stuff
-#if !defined(NDEBUG) && defined(_MSC_VER)
+#if defined(_MSC_VER)
 		struct eh_initializer
 		{
 			eh_initializer()
 			{
+#ifndef NDEBUG
 				_clearfp();
 				_controlfp(_EM_INEXACT | _EM_UNDERFLOW, _MCW_EM );
+#endif
 				::_set_se_translator(straight_to_debugger);
 			}
 
diff --git a/include/libtorrent/storage.hpp b/include/libtorrent/storage.hpp
index 90f615ee3..2e8758159 100755
--- a/include/libtorrent/storage.hpp
+++ b/include/libtorrent/storage.hpp
@@ -34,6 +34,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_STORAGE_HPP_INCLUDE
 
 #include <vector>
+#include <bitset>
 
 #include <boost/limits.hpp>
 #include <boost/filesystem/path.hpp>
@@ -103,6 +104,12 @@ namespace libtorrent
 		void allocate_slots(int num_slots);
 		void mark_failed(int index);
 
+		unsigned long piece_crc(
+			int slot_index
+			, int block_size
+			, const std::bitset<256>& bitmask);
+		int slot_for_piece(int piece_index) const;
+
 		size_type read(char* buf, int piece_index, size_type offset, size_type size);
 		void write(const char* buf, int piece_index, size_type offset, size_type size);
 
diff --git a/src/identify_client.cpp b/src/identify_client.cpp
index 773c6d749..113979c4e 100755
--- a/src/identify_client.cpp
+++ b/src/identify_client.cpp
@@ -201,6 +201,12 @@ namespace libtorrent
 		// non standard encodings
 		// ----------------------
 
+		if (std::equal(PID, PID + 4, "exbc"))
+		{
+			std::stringstream s;
+			s << "BitComet " << (int)PID[4] << "." << (int)PID[5]/10 << (int)PID[5]%10;
+			return s.str();
+		}
 
 		if (std::equal(PID + 5, PID + 5 + 8, "Azureus"))
 		{
@@ -214,7 +220,7 @@ namespace libtorrent
 
 		if (std::equal(PID, PID + 7, "btfans"))
 		{
-			return "BitComet";
+			return "SimpleBT";
 		}
 
 		if (std::equal(PID, PID + 8, "turbobt"))
diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index 0bdbfbfdb..9bd7cf7e8 100755
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -1455,8 +1455,7 @@ namespace libtorrent
 		// if we have requests or pending data to be sent or announcements to be made
 		// we want to send data
 		return ((!m_requests.empty() && !m_choked)
-			|| !m_send_buffer.empty()
-			|| !m_announce_queue.empty())
+			|| !m_send_buffer.empty())
 			&& m_send_quota_left != 0;
 	}
 
@@ -1634,7 +1633,11 @@ namespace libtorrent
 	{
 		boost::posix_time::time_duration d;
 		d = boost::posix_time::second_clock::local_time() - m_last_sent;
-		if (d.seconds() > m_timeout / 2)
+		if (d.seconds() < m_timeout / 2) return;
+
+		// we must either send a keep-alive
+		// message or something else.
+		if (m_announce_queue.empty())
 		{
 			char noop[] = {0,0,0,0};
 			m_send_buffer.insert(m_send_buffer.end(), noop, noop+4);
@@ -1642,11 +1645,23 @@ namespace libtorrent
 	#ifndef NDEBUG
 			(*m_logger) << " ==> NOP\n";
 	#endif
-			send_buffer_updated();
 		}
+		else
+		{
+			for (std::vector<int>::iterator i = m_announce_queue.begin();
+				i != m_announce_queue.end();
+				++i)
+			{
+				send_have(*i);
+			}
+			m_announce_queue.clear();
+		}
+		send_buffer_updated();
 	}
 
 	// TODO: this could be implemented more efficient
+	// by maintaining a counter of the number of pieces
+	// the peer has
 	bool peer_connection::is_seed() const
 	{
 		return std::count(m_have_piece.begin(), m_have_piece.end(), true)
diff --git a/src/policy.cpp b/src/policy.cpp
index 2451da781..d42f1bae7 100755
--- a/src/policy.cpp
+++ b/src/policy.cpp
@@ -280,13 +280,6 @@ namespace
 
 namespace libtorrent
 {
-/*
-	TODO: implement some kind of limit of the number of sockets
-	opened, to use for systems where a user has a limited number
-	of open file descriptors. and for windows which has a buggy tcp-stack.
-	This means also to implement a 'connecion purger', that identifies
-	more or less useless connections and closes them.
-*/
 
 	policy::policy(torrent* t)
 		: m_num_peers(0)
@@ -624,6 +617,8 @@ namespace libtorrent
 	{
 		assert(!c.is_local());
 
+		// TODO: make an exception if the incoming connection
+		// is from the tracker
 		if(m_torrent->num_peers() >= m_max_connections)
 			throw protocol_error("too many connections, refusing incoming connection"); // cause a disconnect
 
@@ -893,6 +888,7 @@ namespace libtorrent
 	{
 		assert(max_connections > 1 || max_connections == -1);
 		if (max_connections == -1) max_connections = std::numeric_limits<int>::max();
+		assert(max_connections >= 2);
 		m_max_connections = max_connections;
 	}
 
diff --git a/src/session.cpp b/src/session.cpp
index 934adb6c1..b1ae5b952 100755
--- a/src/session.cpp
+++ b/src/session.cpp
@@ -378,6 +378,7 @@ namespace libtorrent
 			{
 				m_connections.erase(m_disconnect_peer.back());
 				m_disconnect_peer.pop_back();
+				assert(m_selector.count_read_monitors() == m_connections.size() + 1);
 			}
 		}
 
@@ -500,12 +501,19 @@ namespace libtorrent
 							assert(p->second->get_socket()->is_writable());
 							p->second->send_data();
 						}
-						catch(std::exception&)
+						catch(std::exception& e)
 						{
-							// the connection wants to disconnect for some reason, remove it
-							// from the connection-list
+							// the connection wants to disconnect for some reason,
+							// remove it from the connection-list
+							if (m_alerts.should_post(alert::debug))
+							{
+								m_alerts.post_alert(
+									peer_error_alert(p->second->get_peer_id(), e.what()));
+							}
+
 							m_selector.remove(*i);
 							m_connections.erase(p);
+							assert(m_selector.count_read_monitors() == m_connections.size() + 1);
 						}
 					}
 				}
@@ -558,10 +566,6 @@ namespace libtorrent
 						{
 //							(*m_logger) << "readable: " << p->first->sender().as_string() << "\n";
 							p->second->receive_data();
-
-#ifndef NDEBUG
-							assert_invariant();
-#endif
 						}
 						catch(std::exception& e)
 						{
@@ -574,6 +578,7 @@ namespace libtorrent
 							// from the connection-list
 							m_selector.remove(*i);
 							m_connections.erase(p);
+							assert(m_selector.count_read_monitors() == m_connections.size() + 1);
 						}
 					}
 				}
@@ -593,10 +598,21 @@ namespace libtorrent
 					++i)
 				{
 					connection_map::iterator p = m_connections.find(*i);
+					if (m_alerts.should_post(alert::debug))
+					{
+						m_alerts.post_alert(
+							peer_error_alert(
+								p->second->get_peer_id()
+								, "socket received an exception"));
+					}
 
 					m_selector.remove(*i);
 					// the connection may have been disconnected in the receive or send phase
-					if (p != m_connections.end()) m_connections.erase(p);
+					if (p != m_connections.end())
+					{
+						m_connections.erase(p);
+						assert(m_selector.count_read_monitors() == m_connections.size() + 1);
+					}
 				}
 
 #ifndef NDEBUG
@@ -631,6 +647,7 @@ namespace libtorrent
 					{
 						m_selector.remove(j->first);
 						m_connections.erase(j);
+						assert(m_selector.count_read_monitors() == m_connections.size() + 1);
 						continue;
 					}
 
@@ -1018,6 +1035,34 @@ namespace libtorrent
 							p.finished_blocks[bit] = true;
 					}
 				}
+
+				if (p.finished_blocks.count() == 0) continue;
+
+				std::vector<int>::iterator slot_iter
+					= std::find(tmp_pieces.begin(), tmp_pieces.end(), p.index);
+				if (slot_iter == tmp_pieces.end())
+				{
+					// this piece is marked as unfinished
+					// but doesn't have any storage
+					return;
+				}
+
+				assert(*slot_iter == p.index);
+				int slot_index = slot_iter - tmp_pieces.begin();
+				unsigned long adler
+					= torrent_ptr->filesystem().piece_crc(
+						slot_index
+						, torrent_ptr->block_size()
+						, p.finished_blocks);
+
+				entry::dictionary_type::iterator ad = i->dict().find("adler32");
+				if (ad != i->dict().end())
+				{
+					// crc's didn't match, don't use the resume data
+					if (ad->second.integer() != adler)
+						return;
+				}
+
 				tmp_unfinished.push_back(p);
 			}
 
diff --git a/src/storage.cpp b/src/storage.cpp
index 790a5757f..006ae7477 100755
--- a/src/storage.cpp
+++ b/src/storage.cpp
@@ -427,6 +427,13 @@ namespace libtorrent
 		void allocate_slots(int num_slots);
 		void mark_failed(int index);
 
+		unsigned long piece_crc(
+			int slot_index
+			, int block_size
+			, const std::bitset<256>& bitmask);
+
+		int slot_for_piece(int piece_index) const;
+
 		size_type read(char* buf, int piece_index, size_type offset, size_type size);
 		void write(const char* buf, int piece_index, size_type offset, size_type size);
 
@@ -438,17 +445,15 @@ namespace libtorrent
 	private:
 		// returns the slot currently associated with the given
 		// piece or assigns the given piece_index to a free slot
-		int slot_for_piece(int piece_index);
+		int allocate_slot_for_piece(int piece_index);
 #ifndef NDEBUG
 		void check_invariant() const;
+#ifdef TORRENT_STORAGE_DEBUG
 		void debug_log() const;
+#endif
 #endif
 		storage m_storage;
 
-		// total number of bytes left to be downloaded
-		// TODO: this member shouldn't be necessaty any more
-		size_type m_bytes_left;
-
 		// a bitmask representing the pieces we have
 		std::vector<bool> m_have_piece;
 
@@ -571,6 +576,57 @@ namespace libtorrent
 		m_pimpl->mark_failed(index);
 	}
 
+	int piece_manager::slot_for_piece(int piece_index) const
+	{
+		return m_pimpl->slot_for_piece(piece_index);
+	}
+
+	int piece_manager::impl::slot_for_piece(int piece_index) const
+	{
+		assert(piece_index >= 0 && piece_index < m_info.num_pieces());
+		return m_piece_to_slot[piece_index];
+	}
+
+	unsigned long piece_manager::piece_crc(
+		int index
+		, int block_size
+		, const std::bitset<256>& bitmask)
+	{
+		return m_pimpl->piece_crc(index, block_size, bitmask);
+	}
+
+	unsigned long piece_manager::impl::piece_crc(
+		int slot_index
+		, int block_size
+		, const std::bitset<256>& bitmask)
+	{
+		adler32_crc crc;
+		std::vector<char> buf(block_size);
+		int num_blocks = m_info.piece_size(slot_index) / block_size;
+		int last_block_size = m_info.piece_size(slot_index) % block_size;
+		if (last_block_size == 0) last_block_size = block_size;
+
+		for (int i = 0; i < num_blocks-1; ++i)
+		{
+			if (!bitmask[i]) continue;
+			m_storage.read(
+				&buf[0]
+				, slot_index
+				, i * block_size
+				, block_size);
+			crc.update(&buf[0], block_size);
+		}
+		if (bitmask[num_blocks - 1])
+		{
+			m_storage.read(
+				&buf[0]
+				, slot_index
+				, block_size * (num_blocks - 1)
+				, last_block_size);
+			crc.update(&buf[0], last_block_size);
+		}
+		return crc.final();
+	}
 
 	size_type piece_manager::impl::read(
 		char* buf
@@ -598,7 +654,7 @@ namespace libtorrent
 	  , size_type offset
 	  , size_type size)
 	{
-		int slot = slot_for_piece(piece_index);
+		int slot = allocate_slot_for_piece(piece_index);
 		m_storage.write(buf, slot, offset, size);
 	}
 
@@ -626,8 +682,6 @@ namespace libtorrent
 		m_piece_to_slot.resize(m_info.num_pieces(), has_no_slot);
 		m_slot_to_piece.resize(m_info.num_pieces(), unallocated);
 
-		m_bytes_left = m_info.total_size();
-
 		const std::size_t piece_size = m_info.piece_length();
 		const std::size_t last_piece_size = m_info.piece_size(
 				m_info.num_pieces() - 1);
@@ -655,7 +709,6 @@ namespace libtorrent
 						, piece_picker::has_index(found_piece))
 						== data.unfinished_pieces.end())
 					{
-						m_bytes_left -= m_info.piece_size(found_piece);
 						pieces[found_piece] = true;
 					}
 				}
@@ -832,10 +885,6 @@ namespace libtorrent
 					m_slot_to_piece[m_piece_to_slot[found_piece]] = unassigned;
 					m_free_slots.push_back(m_piece_to_slot[found_piece]);
 				}
-				else
-				{
-					m_bytes_left -= m_info.piece_size(found_piece);
-				}
 
 				m_piece_to_slot[found_piece] = current_slot;
 				m_slot_to_piece[current_slot] = found_piece;
@@ -892,7 +941,7 @@ namespace libtorrent
 		m_pimpl->check_pieces(mutex, data, pieces);
 	}
 	
-	int piece_manager::impl::slot_for_piece(int piece_index)
+	int piece_manager::impl::allocate_slot_for_piece(int piece_index)
 	{
 		// synchronization ------------------------------------------------------
 		boost::recursive_mutex::scoped_lock lock(m_mutex);
@@ -979,7 +1028,9 @@ namespace libtorrent
 			assert(m_piece_to_slot[piece_at_our_slot] == piece_index);
 #ifndef NDEBUG
 			print_to_log(s.str());
+#ifdef TORRENT_STORAGE_DEBUG
 			debug_log();
+#endif
 #endif
 			std::swap(
 				m_slot_to_piece[piece_index]
@@ -997,7 +1048,7 @@ namespace libtorrent
 			assert(m_piece_to_slot[piece_index] == piece_index);
 
 			slot_index = piece_index;
-#ifndef NDEBUG
+#if !defined(NDEBUG) && defined(TORRENT_STORAGE_DEBUG)
 			debug_log();
 #endif
 		}
@@ -1098,7 +1149,8 @@ namespace libtorrent
 			{
 				assert(m_slot_to_piece[i]<m_piece_to_slot.size());
 				assert(m_piece_to_slot[m_slot_to_piece[i]]==i);
-/*				assert(
+#ifdef TORRENT_STORAGE_DEBUG
+				assert(
 					std::find(
 						m_unallocated_slots.begin()
 						, m_unallocated_slots.end()
@@ -1110,25 +1162,30 @@ namespace libtorrent
 						, m_free_slots.end()
 						, i) == m_free_slots.end()
 				);
-*/			}
+#endif
+			}
 			else if (m_slot_to_piece[i] == unallocated)
 			{
-/*				assert(
+#ifdef TORRENT_STORAGE_DEBUG
+				assert(
 					std::find(
 						m_unallocated_slots.begin()
 						, m_unallocated_slots.end()
 						, i) != m_unallocated_slots.end()
 				);
-*/			}
+#endif
+			}
 			else if (m_slot_to_piece[i] == unassigned)
 			{
-/*				assert(
+#ifdef TORRENT_STORAGE_DEBUG
+				assert(
 					std::find(
 						m_free_slots.begin()
 						, m_free_slots.end()
 						, i) != m_free_slots.end()
 				);
-*/			}
+#endif
+			}
 			else
 			{
 				assert(false && "m_slot_to_piece[i] is invalid");
@@ -1136,6 +1193,7 @@ namespace libtorrent
 		}
 	}
 
+#ifdef TORRENT_STORAGE_DEBUG
 	void piece_manager::impl::debug_log() const
 	{
 		std::stringstream s;
@@ -1153,5 +1211,6 @@ namespace libtorrent
 		print_to_log(s.str());
 	}
 #endif
+#endif
 } // namespace libtorrent
 
diff --git a/src/torrent_handle.cpp b/src/torrent_handle.cpp
index 0aa668397..886d2ac6e 100755
--- a/src/torrent_handle.cpp
+++ b/src/torrent_handle.cpp
@@ -94,7 +94,6 @@ namespace libtorrent
 
 	void torrent_handle::set_max_connections(int max_connections)
 	{
-		assert(max_connections >= 2);
 		if (m_ses == 0) throw invalid_handle();
 
 		{
@@ -240,13 +239,17 @@ namespace libtorrent
 			i != q.end();
 			++i)
 		{
+			if (i->finished_blocks.count() == 0) continue;
+
 			entry::dictionary_type piece_struct;
 
 			// the unfinished piece's index
 			piece_struct["piece"] = i->index;
 
 			std::string bitmask;
-			const int num_bitmask_bytes = std::max(num_blocks_per_piece / 8, 1);
+			const int num_bitmask_bytes
+				= std::max(num_blocks_per_piece / 8, 1);
+
 			for (int j = 0; j < num_bitmask_bytes; ++j)
 			{
 				unsigned char v = 0;
@@ -256,7 +259,14 @@ namespace libtorrent
 			}
 			piece_struct["bitmask"] = bitmask;
 
-			// TODO: add a hash to piece_struct
+			assert(t->filesystem().slot_for_piece(i->index) >= 0);
+			unsigned long adler
+				= t->filesystem().piece_crc(
+					t->filesystem().slot_for_piece(i->index)
+					, t->block_size()
+					, i->finished_blocks);
+
+			piece_struct["adler32"] = adler;
 
 			// push the struct onto the unfinished-piece list
 			up.push_back(piece_struct);
diff --git a/src/torrent_info.cpp b/src/torrent_info.cpp
index 3a9b711cf..147b06728 100755
--- a/src/torrent_info.cpp
+++ b/src/torrent_info.cpp
@@ -131,6 +131,20 @@ namespace libtorrent
 			m_urls.push_back(e);
 		}
 
+		// extract creation date
+		i = dict.find("creation date");
+		if (i != dict.end() && i->second.type() == entry::int_t)
+		{
+			m_creation_date = m_creation_date + boost::posix_time::seconds(i->second.integer());
+		}
+
+		// extract comment
+		i = dict.find("comment");
+		if (i != dict.end() && i->second.type() == entry::string_t)
+		{
+			m_comment = i->second.string();
+		}
+
 		i = dict.find("info");
 		if (i == dict.end()) throw invalid_torrent_file();
 		entry info = i->second;
@@ -170,20 +184,6 @@ namespace libtorrent
 			extract_files(i->second.list(), m_files, m_name);
 		}
 
-		// extract creation date
-		i = info.dict().find("creation date");
-		if (i != info.dict().end() && i->second.type() == entry::int_t)
-		{
-			m_creation_date = m_creation_date + boost::posix_time::seconds(i->second.integer());
-		}
-
-		// extract comment
-		i = info.dict().find("comment");
-		if (i != info.dict().end() && i->second.type() == entry::string_t)
-		{
-			m_comment = i->second.string();
-		}
-
 		// calculate total size of all pieces
 		m_total_size = 0;
 		for (std::vector<file_entry>::iterator i = m_files.begin(); i != m_files.end(); ++i)