private void Compact(CharVector kx, iText.Layout.Hyphenation.TernaryTree map, char p) { int k; if (p == 0) { return; } if (sc[p] == 0xFFFF) { k = map.Find(kv.GetArray(), lo[p]); if (k < 0) { k = kx.Alloc(Strlen(kv.GetArray(), lo[p]) + 1); Strcpy(kx.GetArray(), k, kv.GetArray(), lo[p]); map.Insert(kx.GetArray(), k, (char)k); } lo[p] = (char)k; } else { Compact(kx, map, lo[p]); if (sc[p] != 0) { Compact(kx, map, eq[p]); } Compact(kx, map, hi[p]); } }
// With uniform letter distribution sc[root] should be around 'm' // System.out.print("After root splitchar = "); System.out.println(sc[root]); /// <summary> /// Each node stores a character (splitchar) which is part of /// some key(s). /// </summary> /// <remarks> /// Each node stores a character (splitchar) which is part of /// some key(s). In a compressed branch (one that only contain /// a single string key) the trailer of the key which is not /// already in nodes is stored externally in the kv array. /// As items are inserted, key substrings decrease. /// Some substrings may completely disappear when the whole /// branch is totally decompressed. /// The tree is traversed to find the key substrings actually /// used. In addition, duplicate substrings are removed using /// a map (implemented with a TernaryTree!). /// </remarks> public virtual void TrimToSize() { // first balance the tree for best performance Balance(); // redimension the node arrays RedimNodeArrays(freenode); // ok, compact kv array CharVector kx = new CharVector(); kx.Alloc(1); iText.Layout.Hyphenation.TernaryTree map = new iText.Layout.Hyphenation.TernaryTree(); Compact(kx, map, root); kv = kx; kv.TrimToSize(); }
/// <summary>The actual insertion function, recursive version.</summary> private char Insert(char p, char[] key, int start, char val) { int len = Strlen(key, start); if (p == 0) { // this means there is no branch, this node will start a new branch. // Instead of doing that, we store the key somewhere else and create // only one node with a pointer to the key p = freenode++; eq[p] = val; // holds data length++; hi[p] = (char)0; if (len > 0) { sc[p] = (char)0xFFFF; // indicates branch is compressed lo[p] = (char)kv.Alloc(len + 1); // use 'lo' to hold pointer to key Strcpy(kv.GetArray(), lo[p], key, start); } else { sc[p] = (char)0; lo[p] = (char)0; } return(p); } if (sc[p] == 0xFFFF) { // branch is compressed: need to decompress // this will generate garbage in the external key array // but we can do some garbage collection later char pp = freenode++; lo[pp] = lo[p]; // previous pointer to key eq[pp] = eq[p]; // previous pointer to data lo[p] = (char)0; if (len > 0) { sc[p] = kv.Get(lo[pp]); eq[p] = pp; lo[pp]++; if (kv.Get(lo[pp]) == 0) { // key completly decompressed leaving garbage in key array lo[pp] = (char)0; sc[pp] = (char)0; hi[pp] = (char)0; } else { // we only got first char of key, rest is still there sc[pp] = (char)0xFFFF; } } else { // In this case we can save a node by swapping the new node // with the compressed node sc[pp] = (char)0xFFFF; hi[p] = pp; sc[p] = (char)0; eq[p] = val; length++; return(p); } } char s = key[start]; if (s < sc[p]) { lo[p] = Insert(lo[p], key, start, val); } else { if (s == sc[p]) { if (s != 0) { eq[p] = Insert(eq[p], key, start + 1, val); } else { // key already in tree, overwrite data eq[p] = val; } } else { hi[p] = Insert(hi[p], key, start, val); } } return(p); }