Add the source files for the swift library.

[swifty.git] / src / libswift / ext / seq_picker.cpp

diff --git a/src/libswift/ext/seq_picker.cpp b/src/libswift/ext/seq_picker.cpp
new file mode 100644 (file)
index 0000000..2be5206
--- /dev/null
+++ b/src/libswift/ext/seq_picker.cpp
@@ -0,0 +1,82 @@
+/*
+ *  seq_picker.cpp
+ *  swift
+ *
+ *  Created by Victor Grishchenko on 10/6/09.
+ *  Copyright 2009-2012 TECHNISCHE UNIVERSITEIT DELFT. All rights reserved.
+ *
+ */
+
+#include "swift.h"
+#include <cassert>
+
+using namespace swift;
+
+
+/** Picks pieces nearly sequentialy; some local randomization (twisting)
+    is introduced to prevent synchronization among multiple channels. */
+class SeqPiecePicker : public PiecePicker {
+
+    binmap_t        ack_hint_out_;
+    tbqueue         hint_out_;
+    FileTransfer*   transfer_;
+    uint64_t        twist_;
+    bin_t           range_;
+
+public:
+
+    SeqPiecePicker (FileTransfer* file_to_pick_from) : ack_hint_out_(),
+           transfer_(file_to_pick_from), twist_(0), range_(bin_t::ALL) {
+        binmap_t::copy(ack_hint_out_, file().ack_out());
+    }
+    virtual ~SeqPiecePicker() {}
+
+    HashTree& file() {
+        return transfer_->file();
+    }
+
+    virtual void Randomize (uint64_t twist) {
+        twist_ = twist;
+    }
+
+    virtual void LimitRange (bin_t range) {
+        range_ = range;
+    }
+
+    virtual bin_t Pick (binmap_t& offer, uint64_t max_width, tint expires) {
+        while (hint_out_.size() && hint_out_.front().time<NOW-TINT_SEC*3/2) { // FIXME sec
+            binmap_t::copy(ack_hint_out_, file().ack_out(), hint_out_.front().bin);
+            hint_out_.pop_front();
+        }
+        if (!file().size()) {
+            return bin_t(0,0); // whoever sends it first
+        // Arno, 2011-06-28: Partial fix by Victor. exact_size_known() missing
+        //} else if (!file().exact_size_known()) {
+        //    return bin64_t(0,(file().size()>>10)-1); // dirty
+        }
+    retry:      // bite me
+        twist_ &= (file().peak(0).toUInt()) & ((1<<6)-1);
+
+        bin_t hint = binmap_t::find_complement(ack_hint_out_, offer, twist_);
+        if (hint.is_none()) {
+            return hint; // TODO: end-game mode
+        }
+
+        if (!file().ack_out().is_empty(hint)) { // unhinted/late data
+            binmap_t::copy(ack_hint_out_, file().ack_out(), hint);
+            goto retry;
+        }
+        while (hint.base_length()>max_width)
+            hint = hint.left();
+        assert(ack_hint_out_.is_empty(hint));
+        ack_hint_out_.set(hint);
+        hint_out_.push_back(tintbin(NOW,hint));
+        return hint;
+    }
+
+    void updatePlaybackPos(int size = 1)
+    {
+       return;
+    }
+
+};