Jouni's Incremental BWT integrated into TextCollection

[SXSI/TextCollection.git] / incbwt / bits / rlevector.cpp

diff --git a/incbwt/bits/rlevector.cpp b/incbwt/bits/rlevector.cpp
new file mode 100644 (file)
index 0000000..e07c2b4
--- /dev/null
+++ b/incbwt/bits/rlevector.cpp
@@ -0,0 +1,247 @@
+#include <cstdlib>
+
+#include "rlevector.h"
+#include "../misc/utils.h"
+
+
+namespace CSA
+{
+
+
+RLEVector::RLEVector(std::ifstream& file) :
+  BitVector(file)
+{
+}
+
+RLEVector::RLEVector(RLEEncoder& encoder, usint universe_size) :
+  BitVector(encoder, universe_size)
+{
+}
+
+RLEVector::~RLEVector()
+{
+}
+
+//--------------------------------------------------------------------------
+
+usint
+RLEVector::rank(usint value, bool at_least)
+{
+  if(value >= this->size) { return this->items; }
+
+  this->valueLoop(value);
+
+  usint idx = this->sample.first + this->cur + 1;
+  if(!at_least && this->val > value)
+  {
+    idx--;
+  }
+  if(at_least && this->val < value)
+  {
+    this->getSample(this->block + 1);
+    this->run = 0;
+    idx = this->sample.first + this->cur + 1;
+  }
+  return idx;
+}
+
+usint
+RLEVector::select(usint index)
+{
+  if(index >= this->items) { return this->size; }
+  this->getSample(this->sampleForIndex(index));
+  this->run = 0;
+
+  usint lim = index - this->sample.first;
+  while(this->cur < lim)
+  {
+    this->val += this->buffer->readDeltaCode();
+    usint temp = this->buffer->readDeltaCode();
+    this->val += temp - 1;
+    this->cur += temp;
+  }
+  if(this->cur > lim)
+  {
+    this->run = this->cur - lim;
+    this->cur -= this->run;
+    this->val -= this->run;
+  }
+
+  return this->val;
+}
+
+usint
+RLEVector::selectNext()
+{
+  if(this->cur >= this->block_items)
+  {
+    this->getSample(this->block + 1);
+    this->run = 0;
+    return this->val;
+  }
+
+  this->cur++;
+  if(this->run > 0)
+  {
+    this->val++;
+    this->run--;
+  }
+  else
+  {
+    this->val += this->buffer->readDeltaCode();
+    this->run = this->buffer->readDeltaCode() - 1;
+  }
+
+  return this->val;
+}
+
+pair_type
+RLEVector::valueAfter(usint value)
+{
+  if(value >= this->size) { return pair_type(this->size, this->items); }
+
+  this->valueLoop(value);
+
+  if(this->val < value)
+  {
+    this->getSample(this->block + 1);
+    this->run = 0;
+  }
+
+  return pair_type(this->val, this->sample.first + this->cur);
+}
+
+pair_type
+RLEVector::nextValue()
+{
+  if(this->cur >= this->block_items)
+  {
+    this->getSample(this->block + 1);
+    this->run = 0;
+    return pair_type(this->val, this->sample.first);
+  }
+
+  this->cur++;
+  if(this->run > 0)
+  {
+    this->val++;
+    this->run--;
+  }
+  else
+  {
+    this->val += this->buffer->readDeltaCode();
+    this->run = this->buffer->readDeltaCode() - 1;
+  }
+
+  return pair_type(this->val, this->sample.first + this->cur);
+}
+
+pair_type
+RLEVector::selectRun(usint index, usint max_length)
+{
+  usint value = this->select(index);
+
+  usint len = std::min(max_length, this->run);
+  this->run -= len; this->cur += len; this->val += len;
+
+  return pair_type(value, len);
+}
+
+pair_type
+RLEVector::selectNextRun(usint max_length)
+{
+  usint value = this->selectNext();
+
+  usint len = std::min(max_length, this->run);
+  this->run -= len; this->cur += len; this->val += len;
+
+  return pair_type(value, len);
+}
+
+bool
+RLEVector::isSet(usint value)
+{
+  if(value >= this->size) { return false; }
+
+  this->valueLoop(value);
+
+  return (this->val == value);
+}
+
+//--------------------------------------------------------------------------
+
+usint
+RLEVector::reportSize()
+{
+  usint bytes = sizeof(*this);
+  bytes += BitVector::reportSize();
+  return bytes;
+}
+
+//--------------------------------------------------------------------------
+
+RLEEncoder::RLEEncoder(usint block_bytes, usint superblock_size) :
+  VectorEncoder(block_bytes, superblock_size)
+{
+}
+
+RLEEncoder::~RLEEncoder()
+{
+}
+
+void
+RLEEncoder::setRun(usint start, usint len)
+{
+  if(this->items == 0)
+  {
+    this->setFirstBit(start);
+    if(len > 1)
+    {
+      this->RLEncode(1, len - 1);
+    }
+    return;
+  }
+  if(start < this->size || len == 0) { return; }
+
+  // Write as much into the buffer as possible.
+  usint diff = start + 1 - this->size;
+  usint free_bits = this->buffer->bitsLeft();
+  usint code_bits = this->buffer->deltaCodeLength(diff);
+  if(free_bits > code_bits) // At least a part of the run fits into the block.
+  {
+    free_bits -= code_bits;
+    usint run_bits = this->buffer->deltaCodeLength(len);
+    if(run_bits <= free_bits)
+    {
+      this->RLEncode(diff, len);
+      return;
+    }
+
+    // Encode as much as possible and let the rest spill.
+    usint llen = 1;
+    while(llen + 2 * length(llen + 1) - 1 <= free_bits) { llen++; }
+    llen = ((usint)1 << llen) - 1;
+
+    this->RLEncode(diff, llen);
+    len -= llen;
+
+    // A new sample will be added.
+    this->size++;
+    this->items++;
+  }
+  else
+  {
+    this->size = start + 1;
+    this->items++;
+  }
+
+  // Didn't fit into the block. A new sample & block required.
+  this->addNewBlock();
+  if(len > 1)
+  {
+    this->RLEncode(1, len - 1);
+  }
+}
+
+
+} // namespace CSA