/// <summary> /// Not documented /// </summary> /// <param name="dh"> </param> /// <param name="elems"> </param> /// <param name="minCodes"> </param> /// <param name="maxLength"> </param> public Tree(DeflaterHuffman dh, int elems, int minCodes, int maxLength) { this.dh = dh; minNumCodes = minCodes; this.maxLength = maxLength; freqs = new short[elems]; bl_counts = new int[maxLength]; }
/// <summary> /// Construct instance with pending buffer /// </summary> /// <param name="pending"> Pending buffer to use </param> /// > public DeflaterEngine(DeflaterPending pending) { this.pending = pending; huffman = new DeflaterHuffman(pending); adler = new Adler32(); window = new byte[2 * WSIZE]; head = new short[HASH_SIZE]; prev = new short[WSIZE]; // We start at index 1, to avoid an implementation deficiency, that // we cannot build a repeat pattern at index 0. blockStart = strstart = 1; }
/// <summary> /// </summary> /// <param name="codeLengths"> </param> private void BuildTree(byte[] codeLengths) { var blCount = new int[MAX_BITLEN + 1]; var nextCode = new int[MAX_BITLEN + 1]; for (int i = 0; i < codeLengths.Length; i++) { int bits = codeLengths[i]; if (bits > 0) { blCount[bits]++; } } int code = 0; int treeSize = 512; for (int bits = 1; bits <= MAX_BITLEN; bits++) { nextCode[bits] = code; code += blCount[bits] << (16 - bits); if (bits >= 10) { /* We need an extra table for bit lengths >= 10. */ int start = nextCode[bits] & 0x1ff80; int end = code & 0x1ff80; treeSize += (end - start) >> (16 - bits); } } /* -jr comment this out! doesnt work for dynamic trees and pkzip 2.04g * if (code != 65536) * { * throw new SharpZipBaseException("Code lengths don't add up properly."); * } */ /* Now create and fill the extra tables from longest to shortest * bit len. This way the sub trees will be aligned. */ tree = new short[treeSize]; int treePtr = 512; for (int bits = MAX_BITLEN; bits >= 10; bits--) { int end = code & 0x1ff80; code -= blCount[bits] << (16 - bits); int start = code & 0x1ff80; for (int i = start; i < end; i += 1 << 7) { tree[DeflaterHuffman.BitReverse(i)] = (short)((-treePtr << 4) | bits); treePtr += 1 << (bits - 9); } } for (int i = 0; i < codeLengths.Length; i++) { int bits = codeLengths[i]; if (bits == 0) { continue; } code = nextCode[bits]; int revcode = DeflaterHuffman.BitReverse(code); if (bits <= 9) { do { tree[revcode] = (short)((i << 4) | bits); revcode += 1 << bits; } while (revcode < 512); } else { int subTree = tree[revcode & 511]; int treeLen = 1 << (subTree & 15); subTree = -(subTree >> 4); do { tree[subTree | (revcode >> 9)] = (short)((i << 4) | bits); revcode += 1 << bits; } while (revcode < treeLen); } nextCode[bits] = code + (1 << (16 - bits)); } }
/// <summary> /// Construct instance with pending buffer /// </summary> /// <param name="pending"> Pending buffer to use </param> /// > public DeflaterEngine(DeflaterPending pending) { this.pending = pending; huffman = new DeflaterHuffman(pending); adler = new Adler32(); window = new byte[2*WSIZE]; head = new short[HASH_SIZE]; prev = new short[WSIZE]; // We start at index 1, to avoid an implementation deficiency, that // we cannot build a repeat pattern at index 0. blockStart = strstart = 1; }
/// <summary> /// Not documented /// </summary> /// <param name="dh"> </param> /// <param name="elems"> </param> /// <param name="minCodes"> </param> /// <param name="maxLength"> </param> public Tree(DeflaterHuffman dh, int elems, int minCodes, int maxLength) { this.dh = dh; minNumCodes = minCodes; this.maxLength = maxLength; freqs = new short[elems]; bl_counts = new int[maxLength]; }