internal UidSpaceMapper(long strideLength, long newBaseUid, long oldBaseUid, long numUrls, string fileName)
{
this.oldBaseUid = oldBaseUid;
this.newBaseUid = newBaseUid;
this.numUrls = numUrls;
this.strideLength = strideLength;
using (var stream = new BufferedStream(new FileStream(fileName, FileMode.Open, FileAccess.Read))) {
this.bytes = new CachedStream(stream, (ulong)stream.Length);
this.deco = new VarNybbleIntStreamDecompressor(this.bytes);
}
// Construct the index by parsing this.bytes
long numIdxItems = (numUrls / strideLength) + 1;
this.idxPosition = new ulong[numIdxItems];
this.idxGapSum = new ulong[numIdxItems];
ulong gapSum = 0;
int p = 0;
for (long i = 0; i <= numUrls; i++) {
if (i % strideLength == 0) {
this.idxPosition[p] = deco.GetPosition();
this.idxGapSum[p] = gapSum;
p++;
}
if (i < numUrls) gapSum += deco.GetUInt64();
}
Contract.Assert(p == numIdxItems);
Contract.Assert(deco.AtEnd());
}
private UInt64 word; // bytes 7 (highest-order byte) to lastContBit are payload
#endregion Fields
#region Constructors
internal VarByteIntStreamDecompressor(CachedStream main)
{
this.main = main;
this.pos = 0;
UInt64 len = main.Size;
if ((len % 8) != 0) {
throw new FileFormatException("stream length (" + len + ") is not a multiple of 8");
}
this.nextContBit = -1;
this.lastContBit = 0;
}
private UInt64 pos; // mutable state
#endregion Fields
#region Constructors
internal DummyIntStreamDecompressor(CachedStream main)
{
this.main = main;
this.pos = 0;
}
private UInt64 pos; // mutable state
internal DummyIntStreamDecompressor(CachedStream main)
{
this.main = main;
this.pos = 0;
}
internal void Unload()
{
this.bytes = null;
this.idxUrls = null;
this.idxOffsets = null;
}
internal void Load()
{
Contract.Assert(this.numBytes >= 0);
var sw = System.Diagnostics.Stopwatch.StartNew();
using (var stream = new BufferedStream(new FileStream(this.cell.fileName, FileMode.Open, FileAccess.Read))) {
stream.Seek(this.startPos, SeekOrigin.Begin);
this.bytes = new CachedStream(stream, (ulong)this.numBytes);
}
var secs1 = 0.001 * sw.ElapsedMilliseconds;
sw.Restart();
// Given the data in this.bytes, construct idxUrls and idxOffsets
var numIdxItems = (int)((this.cell.numUrls + this.indexStride - 1) / this.indexStride);
// Note that for numUrls=0 ^^this^^ is NOT the same as (int)((this.cell.numUrls - 1) / this.indexStride) + 1 !!
this.idxUrls = new byte[numIdxItems][];
this.idxOffsets = new ulong[numIdxItems];
ulong pos = 0; // position in this.bytes -- starts at 0
ulong lastPos = 0;
var res = new byte[0];
int resLen = 0;
long cuid = 0;
while (cuid < this.cell.numUrls) {
int prefLen = this.ReadCompressedSize(ref pos);
int suffLen = this.ReadCompressedSize(ref pos);
resLen = prefLen + suffLen;
// Enlarge the result buffer if necessary
if (resLen > res.Length) {
var tmp = new byte[resLen];
for (int i = 0; i < prefLen; i++) { // care only about first prefLen bytes
tmp[i] = res[i];
}
res = tmp;
}
// Read the suffix
for (int i = prefLen; i < resLen; i++) {
res[i] = this.bytes.GetUInt8(pos + (ulong)(i - prefLen));
}
pos += (ulong)suffLen;
if (++cuid % indexStride == 0) {
// Save an index item
int idx = (int)(cuid / indexStride) - 1;
idxUrls[idx] = SubArray(res, 0, resLen);
idxOffsets[idx] = lastPos;
lastPos = pos;
}
}
// Finally, store a sentinel
if (cuid % indexStride != 0) {
idxUrls[numIdxItems - 1] = SubArray(res, 0, resLen);
idxOffsets[numIdxItems - 1] = lastPos;
}
var secs2 = 0.001 * sw.ElapsedMilliseconds;
//Console.Error.WriteLine("PERF: Cell {0} url portion: Loading took {1} seconds, indexing took {2} seconds", this.cell.fileName, secs1, secs2);
Contract.ForAll(this.idxUrls, url => url != null);
}
private byte[][] idxUrls; // each byte[] is logically a UTF8-encoded string
#endregion Fields
#region Constructors
internal UrlCell(Cell cell, BinaryReader rd)
{
this.numBytes = rd.ReadInt64();
this.indexStride = rd.ReadInt32();
this.cell = cell;
this.startPos = -1;
this.idxUrls = null;
this.idxOffsets = null;
this.bytes = null;
this.hashToUidCache = null;
this.hasher = new Hash64();
}
internal void Load()
{
var sw = Stopwatch.StartNew();
// Somewhat of a hack: If this LinkCell is not yet sealed, return immediately.
// This is OK as long as noone tries to use the cell subsequently.
// A better solution would be not to call Load on unsealed LinkCell objects.
if (this.numBytes == -1) return;
using (var rd = new BinaryReader(new BufferedStream(new FileStream(this.cell.fileName, FileMode.Open, FileAccess.Read, FileShare.Read)))) {
rd.BaseStream.Seek(this.startPos, SeekOrigin.Begin);
this.bytes = new CachedStream(rd.BaseStream, (ulong)this.numBytes);
}
var secs1 = 0.001 * sw.ElapsedMilliseconds;
sw.Restart();
// Construct idxOffsets from main
var supraPuid = this.cell.part.ping.PUID(this.cell.supraUID);
long numIdxItems = (int)((supraPuid - 1) / this.indexStride) + 1;
this.idxOffsets = new ulong[numIdxItems];
var decompressor = this.NewDecompressor();
int idx = 0;
for (long puid = 0; puid < supraPuid; puid++) {
if (puid % this.indexStride == 0) {
idxOffsets[idx++] = decompressor.GetPosition();
}
uint m = decompressor.GetUInt32();
for (uint j = 0; j < m; j++) {
var linkUid = decompressor.GetUInt64(); // don't care that first gap is signed
}
}
var secs2 = 0.001 * sw.ElapsedMilliseconds;
//Console.Error.WriteLine("PERF: Cell {0} {1} portion: Loading took {2} seconds, indexing took {3} seconds", this.cell.fileName, this == this.cell.fwdCell ? "fwd" : "bwd", secs1, secs2);
}
internal LinkCell(Cell cell, BinaryReader rd)
{
this.numBytes = rd.ReadInt64();
this.numLinks = rd.ReadInt64();
this.indexStride = rd.ReadInt32();
this.compressionCode = (LinkCompression)rd.ReadUInt32();
this.cell = cell;
this.startPos = -1;
this.idxOffsets = null;
this.bytes = null;
}
