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|
- using System;
- namespace SharpCompress.Compressors.Deflate
- {
- internal sealed partial class DeflateManager
- {
-
- internal static readonly int[] ExtraLengthBits =
- {
- 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
- 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
- };
-
- internal static readonly int[] ExtraDistanceBits =
- {
- 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
- 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13
- };
- internal enum BlockState
- {
- NeedMore = 0,
- BlockDone,
- FinishStarted,
- FinishDone
- }
- internal enum DeflateFlavor
- {
- Store,
- Fast,
- Slow
- }
- private const int MEM_LEVEL_MAX = 9;
- private const int MEM_LEVEL_DEFAULT = 8;
- internal delegate BlockState CompressFunc(FlushType flush);
- internal class Config
- {
-
- internal int GoodLength;
-
-
-
-
- internal int MaxLazy;
- internal int NiceLength;
-
-
- internal int MaxChainLength;
- internal DeflateFlavor Flavor;
- private Config(int goodLength, int maxLazy, int niceLength, int maxChainLength, DeflateFlavor flavor)
- {
- GoodLength = goodLength;
- MaxLazy = maxLazy;
- NiceLength = niceLength;
- MaxChainLength = maxChainLength;
- Flavor = flavor;
- }
- public static Config Lookup(CompressionLevel level)
- {
- return Table[(int)level];
- }
- static Config()
- {
- Table = new[]
- {
- new Config(0, 0, 0, 0, DeflateFlavor.Store),
- new Config(4, 4, 8, 4, DeflateFlavor.Fast),
- new Config(4, 5, 16, 8, DeflateFlavor.Fast),
- new Config(4, 6, 32, 32, DeflateFlavor.Fast),
- new Config(4, 4, 16, 16, DeflateFlavor.Slow),
- new Config(8, 16, 32, 32, DeflateFlavor.Slow),
- new Config(8, 16, 128, 128, DeflateFlavor.Slow),
- new Config(8, 32, 128, 256, DeflateFlavor.Slow),
- new Config(32, 128, 258, 1024, DeflateFlavor.Slow),
- new Config(32, 258, 258, 4096, DeflateFlavor.Slow)
- };
- }
- private static readonly Config[] Table;
- }
- private CompressFunc DeflateFunction;
- private static readonly String[] _ErrorMessage =
- {
- "need dictionary",
- "stream end",
- "",
- "file error",
- "stream error",
- "data error",
- "insufficient memory",
- "buffer error",
- "incompatible version",
- ""
- };
-
- private const int PRESET_DICT = 0x20;
- private const int INIT_STATE = 42;
- private const int BUSY_STATE = 113;
- private const int FINISH_STATE = 666;
-
- private const int Z_DEFLATED = 8;
- private const int STORED_BLOCK = 0;
- private const int STATIC_TREES = 1;
- private const int DYN_TREES = 2;
-
- private const int Z_BINARY = 0;
- private const int Z_ASCII = 1;
- private const int Z_UNKNOWN = 2;
- private const int Buf_size = 8 * 2;
- private const int MIN_MATCH = 3;
- private const int MAX_MATCH = 258;
- private const int MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
- private static readonly int HEAP_SIZE = (2 * InternalConstants.L_CODES + 1);
- private const int END_BLOCK = 256;
- internal ZlibCodec _codec;
- internal int status;
- internal byte[] pending;
- internal int nextPending;
- internal int pendingCount;
- internal sbyte data_type;
- internal int last_flush;
- internal int w_size;
- internal int w_bits;
- internal int w_mask;
-
- internal byte[] window;
-
-
-
-
-
-
-
- internal int window_size;
-
-
- internal short[] prev;
-
-
-
- private short[] head;
- private int ins_h;
- private int hash_size;
- private int hash_bits;
- private int hash_mask;
-
-
-
-
- private int hash_shift;
-
-
- private int blockStart;
- private Config config;
- private int match_length;
- private int prev_match;
- private int match_available;
- private int strstart;
- private int match_start;
- private int lookahead;
-
-
- private int prev_length;
-
-
-
- private CompressionLevel compressionLevel;
- private CompressionStrategy compressionStrategy;
- private readonly short[] dyn_ltree;
- private readonly short[] dyn_dtree;
- private readonly short[] bl_tree;
- private readonly Tree treeLiterals = new Tree();
- private readonly Tree treeDistances = new Tree();
- private readonly Tree treeBitLengths = new Tree();
-
- private readonly short[] bl_count = new short[InternalConstants.MAX_BITS + 1];
-
- private readonly int[] heap = new int[2 * InternalConstants.L_CODES + 1];
- private int heap_len;
- private int heap_max;
-
-
-
- private readonly sbyte[] depth = new sbyte[2 * InternalConstants.L_CODES + 1];
- private int _lengthOffset;
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- internal int lit_bufsize;
- internal int last_lit;
-
-
-
- internal int _distanceOffset;
- internal int opt_len;
- internal int static_len;
- internal int matches;
- internal int last_eob_len;
-
-
- internal short bi_buf;
-
-
- internal int bi_valid;
- internal DeflateManager()
- {
- dyn_ltree = new short[HEAP_SIZE * 2];
- dyn_dtree = new short[(2 * InternalConstants.D_CODES + 1) * 2];
- bl_tree = new short[(2 * InternalConstants.BL_CODES + 1) * 2];
- }
-
- private void _InitializeLazyMatch()
- {
- window_size = 2 * w_size;
-
- Array.Clear(head, 0, hash_size);
-
- config = Config.Lookup(compressionLevel);
- SetDeflater();
- strstart = 0;
- blockStart = 0;
- lookahead = 0;
- match_length = prev_length = MIN_MATCH - 1;
- match_available = 0;
- ins_h = 0;
- }
-
- private void _InitializeTreeData()
- {
- treeLiterals.dyn_tree = dyn_ltree;
- treeLiterals.staticTree = StaticTree.Literals;
- treeDistances.dyn_tree = dyn_dtree;
- treeDistances.staticTree = StaticTree.Distances;
- treeBitLengths.dyn_tree = bl_tree;
- treeBitLengths.staticTree = StaticTree.BitLengths;
- bi_buf = 0;
- bi_valid = 0;
- last_eob_len = 8;
-
- _InitializeBlocks();
- }
- internal void _InitializeBlocks()
- {
-
- for (int i = 0; i < InternalConstants.L_CODES; i++)
- {
- dyn_ltree[i * 2] = 0;
- }
- for (int i = 0; i < InternalConstants.D_CODES; i++)
- {
- dyn_dtree[i * 2] = 0;
- }
- for (int i = 0; i < InternalConstants.BL_CODES; i++)
- {
- bl_tree[i * 2] = 0;
- }
- dyn_ltree[END_BLOCK * 2] = 1;
- opt_len = static_len = 0;
- last_lit = matches = 0;
- }
-
-
-
-
- internal void pqdownheap(short[] tree, int k)
- {
- int v = heap[k];
- int j = k << 1;
- while (j <= heap_len)
- {
-
- if (j < heap_len && IsSmaller(tree, heap[j + 1], heap[j], depth))
- {
- j++;
- }
-
- if (IsSmaller(tree, v, heap[j], depth))
- {
- break;
- }
-
- heap[k] = heap[j];
- k = j;
-
- j <<= 1;
- }
- heap[k] = v;
- }
- internal static bool IsSmaller(short[] tree, int n, int m, sbyte[] depth)
- {
- short tn2 = tree[n * 2];
- short tm2 = tree[m * 2];
- return (tn2 < tm2 || (tn2 == tm2 && depth[n] <= depth[m]));
- }
-
-
- internal void ScanTree(short[] tree, int maxCode)
- {
- int n;
- int prevlen = -1;
- int curlen;
- int nextlen = tree[0 * 2 + 1];
- int count = 0;
- int max_count = 7;
- int min_count = 4;
- if (nextlen == 0)
- {
- max_count = 138;
- min_count = 3;
- }
- tree[(maxCode + 1) * 2 + 1] = 0x7fff;
- for (n = 0; n <= maxCode; n++)
- {
- curlen = nextlen;
- nextlen = tree[(n + 1) * 2 + 1];
- if (++count < max_count && curlen == nextlen)
- {
- continue;
- }
- if (count < min_count)
- {
- bl_tree[curlen * 2] = (short)(bl_tree[curlen * 2] + count);
- }
- else if (curlen != 0)
- {
- if (curlen != prevlen)
- {
- bl_tree[curlen * 2]++;
- }
- bl_tree[InternalConstants.REP_3_6 * 2]++;
- }
- else if (count <= 10)
- {
- bl_tree[InternalConstants.REPZ_3_10 * 2]++;
- }
- else
- {
- bl_tree[InternalConstants.REPZ_11_138 * 2]++;
- }
- count = 0;
- prevlen = curlen;
- if (nextlen == 0)
- {
- max_count = 138;
- min_count = 3;
- }
- else if (curlen == nextlen)
- {
- max_count = 6;
- min_count = 3;
- }
- else
- {
- max_count = 7;
- min_count = 4;
- }
- }
- }
-
-
- internal int BuildBlTree()
- {
- int max_blindex;
-
- ScanTree(dyn_ltree, treeLiterals.max_code);
- ScanTree(dyn_dtree, treeDistances.max_code);
-
- treeBitLengths.build_tree(this);
-
-
-
-
-
- for (max_blindex = InternalConstants.BL_CODES - 1; max_blindex >= 3; max_blindex--)
- {
- if (bl_tree[Tree.bl_order[max_blindex] * 2 + 1] != 0)
- {
- break;
- }
- }
-
- opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
- return max_blindex;
- }
-
-
-
- internal void send_all_trees(int lcodes, int dcodes, int blcodes)
- {
- int rank;
- send_bits(lcodes - 257, 5);
- send_bits(dcodes - 1, 5);
- send_bits(blcodes - 4, 4);
- for (rank = 0; rank < blcodes; rank++)
- {
- send_bits(bl_tree[Tree.bl_order[rank] * 2 + 1], 3);
- }
- send_tree(dyn_ltree, lcodes - 1);
- send_tree(dyn_dtree, dcodes - 1);
- }
-
-
- internal void send_tree(short[] tree, int max_code)
- {
- int n;
- int prevlen = -1;
- int curlen;
- int nextlen = tree[0 * 2 + 1];
- int count = 0;
- int max_count = 7;
- int min_count = 4;
- if (nextlen == 0)
- {
- max_count = 138;
- min_count = 3;
- }
- for (n = 0; n <= max_code; n++)
- {
- curlen = nextlen;
- nextlen = tree[(n + 1) * 2 + 1];
- if (++count < max_count && curlen == nextlen)
- {
- continue;
- }
- if (count < min_count)
- {
- do
- {
- send_code(curlen, bl_tree);
- }
- while (--count != 0);
- }
- else if (curlen != 0)
- {
- if (curlen != prevlen)
- {
- send_code(curlen, bl_tree);
- count--;
- }
- send_code(InternalConstants.REP_3_6, bl_tree);
- send_bits(count - 3, 2);
- }
- else if (count <= 10)
- {
- send_code(InternalConstants.REPZ_3_10, bl_tree);
- send_bits(count - 3, 3);
- }
- else
- {
- send_code(InternalConstants.REPZ_11_138, bl_tree);
- send_bits(count - 11, 7);
- }
- count = 0;
- prevlen = curlen;
- if (nextlen == 0)
- {
- max_count = 138;
- min_count = 3;
- }
- else if (curlen == nextlen)
- {
- max_count = 6;
- min_count = 3;
- }
- else
- {
- max_count = 7;
- min_count = 4;
- }
- }
- }
-
-
- private void put_bytes(byte[] p, int start, int len)
- {
- Array.Copy(p, start, pending, pendingCount, len);
- pendingCount += len;
- }
- #if NOTNEEDED
- private void put_byte(byte c)
- {
- pending[pendingCount++] = c;
- }
- internal void put_short(int b)
- {
- unchecked
- {
- pending[pendingCount++] = (byte)b;
- pending[pendingCount++] = (byte)(b >> 8);
- }
- }
- internal void putShortMSB(int b)
- {
- unchecked
- {
- pending[pendingCount++] = (byte)(b >> 8);
- pending[pendingCount++] = (byte)b;
- }
- }
- #endif
- internal void send_code(int c, short[] tree)
- {
- int c2 = c * 2;
- send_bits((tree[c2] & 0xffff), (tree[c2 + 1] & 0xffff));
- }
- #pragma warning disable 675 // workaround for Visual Studio 2015 compiler bug: https://github.com/dotnet/roslyn/issues/4027
- internal void send_bits(int value, int length)
- {
- int len = length;
- unchecked
- {
- if (bi_valid > Buf_size - len)
- {
-
-
- bi_buf |= (short)((value << bi_valid) & 0xffff);
-
- pending[pendingCount++] = (byte)bi_buf;
- pending[pendingCount++] = (byte)(bi_buf >> 8);
- bi_buf = (short)((uint)value >> (Buf_size - bi_valid));
- bi_valid += len - Buf_size;
- }
- else
- {
-
- bi_buf |= (short)((value << bi_valid) & 0xffff);
- bi_valid += len;
- }
- }
- }
- #pragma warning restore 675
-
-
-
-
-
-
-
-
-
- internal void _tr_align()
- {
- send_bits(STATIC_TREES << 1, 3);
- send_code(END_BLOCK, StaticTree.lengthAndLiteralsTreeCodes);
- bi_flush();
-
-
-
-
- if (1 + last_eob_len + 10 - bi_valid < 9)
- {
- send_bits(STATIC_TREES << 1, 3);
- send_code(END_BLOCK, StaticTree.lengthAndLiteralsTreeCodes);
- bi_flush();
- }
- last_eob_len = 7;
- }
-
-
- internal bool _tr_tally(int dist, int lc)
- {
- pending[_distanceOffset + last_lit * 2] = unchecked((byte)((uint)dist >> 8));
- pending[_distanceOffset + last_lit * 2 + 1] = unchecked((byte)dist);
- pending[_lengthOffset + last_lit] = unchecked((byte)lc);
- last_lit++;
- if (dist == 0)
- {
-
- dyn_ltree[lc * 2]++;
- }
- else
- {
- matches++;
-
- dist--;
- dyn_ltree[(Tree.LengthCode[lc] + InternalConstants.LITERALS + 1) * 2]++;
- dyn_dtree[Tree.DistanceCode(dist) * 2]++;
- }
- if ((last_lit & 0x1fff) == 0 && (int)compressionLevel > 2)
- {
-
- int out_length = last_lit << 3;
- int in_length = strstart - blockStart;
- int dcode;
- for (dcode = 0; dcode < InternalConstants.D_CODES; dcode++)
- {
- out_length =
- (int)(out_length + dyn_dtree[dcode * 2] * (5L + ExtraDistanceBits[dcode]));
- }
- out_length >>= 3;
- if ((matches < (last_lit / 2)) && out_length < in_length / 2)
- {
- return true;
- }
- }
- return (last_lit == lit_bufsize - 1) || (last_lit == lit_bufsize);
-
-
-
-
- }
-
- internal void send_compressed_block(short[] ltree, short[] dtree)
- {
- int distance;
- int lc;
- int lx = 0;
- int code;
- int extra;
- if (last_lit != 0)
- {
- do
- {
- int ix = _distanceOffset + lx * 2;
- distance = ((pending[ix] << 8) & 0xff00) |
- (pending[ix + 1] & 0xff);
- lc = (pending[_lengthOffset + lx]) & 0xff;
- lx++;
- if (distance == 0)
- {
- send_code(lc, ltree);
- }
- else
- {
-
-
- code = Tree.LengthCode[lc];
-
- send_code(code + InternalConstants.LITERALS + 1, ltree);
- extra = ExtraLengthBits[code];
- if (extra != 0)
- {
-
- lc -= Tree.LengthBase[code];
- send_bits(lc, extra);
- }
- distance--;
- code = Tree.DistanceCode(distance);
-
- send_code(code, dtree);
- extra = ExtraDistanceBits[code];
- if (extra != 0)
- {
-
- distance -= Tree.DistanceBase[code];
- send_bits(distance, extra);
- }
- }
-
- }
- while (lx < last_lit);
- }
- send_code(END_BLOCK, ltree);
- last_eob_len = ltree[END_BLOCK * 2 + 1];
- }
-
-
-
-
- internal void set_data_type()
- {
- int n = 0;
- int ascii_freq = 0;
- int bin_freq = 0;
- while (n < 7)
- {
- bin_freq += dyn_ltree[n * 2];
- n++;
- }
- while (n < 128)
- {
- ascii_freq += dyn_ltree[n * 2];
- n++;
- }
- while (n < InternalConstants.LITERALS)
- {
- bin_freq += dyn_ltree[n * 2];
- n++;
- }
- data_type = (sbyte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
- }
-
- internal void bi_flush()
- {
- if (bi_valid == 16)
- {
- pending[pendingCount++] = (byte)bi_buf;
- pending[pendingCount++] = (byte)(bi_buf >> 8);
- bi_buf = 0;
- bi_valid = 0;
- }
- else if (bi_valid >= 8)
- {
-
- pending[pendingCount++] = (byte)bi_buf;
- bi_buf >>= 8;
- bi_valid -= 8;
- }
- }
-
- internal void bi_windup()
- {
- if (bi_valid > 8)
- {
- pending[pendingCount++] = (byte)bi_buf;
- pending[pendingCount++] = (byte)(bi_buf >> 8);
- }
- else if (bi_valid > 0)
- {
-
- pending[pendingCount++] = (byte)bi_buf;
- }
- bi_buf = 0;
- bi_valid = 0;
- }
-
-
- internal void copy_block(int buf, int len, bool header)
- {
- bi_windup();
- last_eob_len = 8;
- if (header)
- {
- unchecked
- {
-
- pending[pendingCount++] = (byte)len;
- pending[pendingCount++] = (byte)(len >> 8);
-
- pending[pendingCount++] = (byte)~len;
- pending[pendingCount++] = (byte)(~len >> 8);
- }
- }
- put_bytes(window, buf, len);
- }
- internal void flush_block_only(bool eof)
- {
- _tr_flush_block(blockStart >= 0 ? blockStart : -1, strstart - blockStart, eof);
- blockStart = strstart;
- _codec.flush_pending();
- }
-
-
-
-
-
-
-
- internal BlockState DeflateNone(FlushType flush)
- {
-
-
- int max_block_size = 0xffff;
- int max_start;
- if (max_block_size > pending.Length - 5)
- {
- max_block_size = pending.Length - 5;
- }
-
- while (true)
- {
-
- if (lookahead <= 1)
- {
- _fillWindow();
- if (lookahead == 0 && flush == FlushType.None)
- {
- return BlockState.NeedMore;
- }
- if (lookahead == 0)
- {
- break;
- }
- }
- strstart += lookahead;
- lookahead = 0;
-
- max_start = blockStart + max_block_size;
- if (strstart == 0 || strstart >= max_start)
- {
-
- lookahead = strstart - max_start;
- strstart = max_start;
- flush_block_only(false);
- if (_codec.AvailableBytesOut == 0)
- {
- return BlockState.NeedMore;
- }
- }
-
-
- if (strstart - blockStart >= w_size - MIN_LOOKAHEAD)
- {
- flush_block_only(false);
- if (_codec.AvailableBytesOut == 0)
- {
- return BlockState.NeedMore;
- }
- }
- }
- flush_block_only(flush == FlushType.Finish);
- if (_codec.AvailableBytesOut == 0)
- {
- return (flush == FlushType.Finish) ? BlockState.FinishStarted : BlockState.NeedMore;
- }
- return flush == FlushType.Finish ? BlockState.FinishDone : BlockState.BlockDone;
- }
-
- internal void _tr_stored_block(int buf, int stored_len, bool eof)
- {
- send_bits((STORED_BLOCK << 1) + (eof ? 1 : 0), 3);
- copy_block(buf, stored_len, true);
- }
-
-
- internal void _tr_flush_block(int buf, int stored_len, bool eof)
- {
- int opt_lenb, static_lenb;
- int max_blindex = 0;
-
- if (compressionLevel > 0)
- {
-
- if (data_type == Z_UNKNOWN)
- {
- set_data_type();
- }
-
- treeLiterals.build_tree(this);
- treeDistances.build_tree(this);
-
-
-
-
- max_blindex = BuildBlTree();
-
- opt_lenb = (opt_len + 3 + 7) >> 3;
- static_lenb = (static_len + 3 + 7) >> 3;
- if (static_lenb <= opt_lenb)
- {
- opt_lenb = static_lenb;
- }
- }
- else
- {
- opt_lenb = static_lenb = stored_len + 5;
- }
- if (stored_len + 4 <= opt_lenb && buf != -1)
- {
-
-
-
-
-
-
- _tr_stored_block(buf, stored_len, eof);
- }
- else if (static_lenb == opt_lenb)
- {
- send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
- send_compressed_block(StaticTree.lengthAndLiteralsTreeCodes, StaticTree.distTreeCodes);
- }
- else
- {
- send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
- send_all_trees(treeLiterals.max_code + 1, treeDistances.max_code + 1, max_blindex + 1);
- send_compressed_block(dyn_ltree, dyn_dtree);
- }
-
-
- _InitializeBlocks();
- if (eof)
- {
- bi_windup();
- }
- }
-
-
-
-
-
-
-
-
- private void _fillWindow()
- {
- int n, m;
- int p;
- int more;
- do
- {
- more = (window_size - lookahead - strstart);
-
- if (more == 0 && strstart == 0 && lookahead == 0)
- {
- more = w_size;
- }
- else if (more == -1)
- {
-
-
- more--;
-
-
- }
- else if (strstart >= w_size + w_size - MIN_LOOKAHEAD)
- {
- Array.Copy(window, w_size, window, 0, w_size);
- match_start -= w_size;
- strstart -= w_size;
- blockStart -= w_size;
-
-
-
-
-
- n = hash_size;
- p = n;
- do
- {
- m = (head[--p] & 0xffff);
- head[p] = (short)((m >= w_size) ? (m - w_size) : 0);
- }
- while (--n != 0);
- n = w_size;
- p = n;
- do
- {
- m = (prev[--p] & 0xffff);
- prev[p] = (short)((m >= w_size) ? (m - w_size) : 0);
-
-
- }
- while (--n != 0);
- more += w_size;
- }
- if (_codec.AvailableBytesIn == 0)
- {
- return;
- }
-
-
-
-
-
-
-
-
-
-
- n = _codec.read_buf(window, strstart + lookahead, more);
- lookahead += n;
-
- if (lookahead >= MIN_MATCH)
- {
- ins_h = window[strstart] & 0xff;
- ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
- }
-
-
- }
- while (lookahead < MIN_LOOKAHEAD && _codec.AvailableBytesIn != 0);
- }
-
-
-
-
-
- internal BlockState DeflateFast(FlushType flush)
- {
-
- int hash_head = 0;
- bool bflush;
- while (true)
- {
-
-
-
-
- if (lookahead < MIN_LOOKAHEAD)
- {
- _fillWindow();
- if (lookahead < MIN_LOOKAHEAD && flush == FlushType.None)
- {
- return BlockState.NeedMore;
- }
- if (lookahead == 0)
- {
- break;
- }
- }
-
-
- if (lookahead >= MIN_MATCH)
- {
- ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
-
- hash_head = (head[ins_h] & 0xffff);
- prev[strstart & w_mask] = head[ins_h];
- head[ins_h] = unchecked((short)strstart);
- }
-
-
- if (hash_head != 0L && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD)
- {
-
-
-
- if (compressionStrategy != CompressionStrategy.HuffmanOnly)
- {
- match_length = longest_match(hash_head);
- }
-
- }
- if (match_length >= MIN_MATCH)
- {
-
- bflush = _tr_tally(strstart - match_start, match_length - MIN_MATCH);
- lookahead -= match_length;
-
-
- if (match_length <= config.MaxLazy && lookahead >= MIN_MATCH)
- {
- match_length--;
- do
- {
- strstart++;
- ins_h = ((ins_h << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
-
- hash_head = (head[ins_h] & 0xffff);
- prev[strstart & w_mask] = head[ins_h];
- head[ins_h] = unchecked((short)strstart);
-
-
- }
- while (--match_length != 0);
- strstart++;
- }
- else
- {
- strstart += match_length;
- match_length = 0;
- ins_h = window[strstart] & 0xff;
- ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
-
-
- }
- }
- else
- {
-
- bflush = _tr_tally(0, window[strstart] & 0xff);
- lookahead--;
- strstart++;
- }
- if (bflush)
- {
- flush_block_only(false);
- if (_codec.AvailableBytesOut == 0)
- {
- return BlockState.NeedMore;
- }
- }
- }
- flush_block_only(flush == FlushType.Finish);
- if (_codec.AvailableBytesOut == 0)
- {
- if (flush == FlushType.Finish)
- {
- return BlockState.FinishStarted;
- }
- return BlockState.NeedMore;
- }
- return flush == FlushType.Finish ? BlockState.FinishDone : BlockState.BlockDone;
- }
-
-
-
- internal BlockState DeflateSlow(FlushType flush)
- {
-
- int hash_head = 0;
- bool bflush;
-
- while (true)
- {
-
-
-
-
- if (lookahead < MIN_LOOKAHEAD)
- {
- _fillWindow();
- if (lookahead < MIN_LOOKAHEAD && flush == FlushType.None)
- {
- return BlockState.NeedMore;
- }
- if (lookahead == 0)
- {
- break;
- }
- }
-
-
- if (lookahead >= MIN_MATCH)
- {
- ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
-
- hash_head = (head[ins_h] & 0xffff);
- prev[strstart & w_mask] = head[ins_h];
- head[ins_h] = unchecked((short)strstart);
- }
-
- prev_length = match_length;
- prev_match = match_start;
- match_length = MIN_MATCH - 1;
- if (hash_head != 0 && prev_length < config.MaxLazy &&
- ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD)
- {
-
-
-
- if (compressionStrategy != CompressionStrategy.HuffmanOnly)
- {
- match_length = longest_match(hash_head);
- }
-
- if (match_length <= 5 && (compressionStrategy == CompressionStrategy.Filtered ||
- (match_length == MIN_MATCH && strstart - match_start > 4096)))
- {
-
-
- match_length = MIN_MATCH - 1;
- }
- }
-
-
- if (prev_length >= MIN_MATCH && match_length <= prev_length)
- {
- int max_insert = strstart + lookahead - MIN_MATCH;
-
-
- bflush = _tr_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
-
-
-
-
- lookahead -= (prev_length - 1);
- prev_length -= 2;
- do
- {
- if (++strstart <= max_insert)
- {
- ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) &
- hash_mask;
-
- hash_head = (head[ins_h] & 0xffff);
- prev[strstart & w_mask] = head[ins_h];
- head[ins_h] = unchecked((short)strstart);
- }
- }
- while (--prev_length != 0);
- match_available = 0;
- match_length = MIN_MATCH - 1;
- strstart++;
- if (bflush)
- {
- flush_block_only(false);
- if (_codec.AvailableBytesOut == 0)
- {
- return BlockState.NeedMore;
- }
- }
- }
- else if (match_available != 0)
- {
-
-
-
- bflush = _tr_tally(0, window[strstart - 1] & 0xff);
- if (bflush)
- {
- flush_block_only(false);
- }
- strstart++;
- lookahead--;
- if (_codec.AvailableBytesOut == 0)
- {
- return BlockState.NeedMore;
- }
- }
- else
- {
-
-
- match_available = 1;
- strstart++;
- lookahead--;
- }
- }
- if (match_available != 0)
- {
- bflush = _tr_tally(0, window[strstart - 1] & 0xff);
- match_available = 0;
- }
- flush_block_only(flush == FlushType.Finish);
- if (_codec.AvailableBytesOut == 0)
- {
- if (flush == FlushType.Finish)
- {
- return BlockState.FinishStarted;
- }
- return BlockState.NeedMore;
- }
- return flush == FlushType.Finish ? BlockState.FinishDone : BlockState.BlockDone;
- }
- internal int longest_match(int cur_match)
- {
- int chain_length = config.MaxChainLength;
- int scan = strstart;
- int match;
- int len;
- int best_len = prev_length;
- int limit = strstart > (w_size - MIN_LOOKAHEAD) ? strstart - (w_size - MIN_LOOKAHEAD) : 0;
- int niceLength = config.NiceLength;
-
-
- int wmask = w_mask;
- int strend = strstart + MAX_MATCH;
- byte scan_end1 = window[scan + best_len - 1];
- byte scan_end = window[scan + best_len];
-
-
-
- if (prev_length >= config.GoodLength)
- {
- chain_length >>= 2;
- }
-
-
- if (niceLength > lookahead)
- {
- niceLength = lookahead;
- }
- do
- {
- match = cur_match;
-
-
- if (window[match + best_len] != scan_end ||
- window[match + best_len - 1] != scan_end1 ||
- window[match] != window[scan] ||
- window[++match] != window[scan + 1])
- {
- continue;
- }
-
-
-
-
-
- scan += 2;
- match++;
-
-
- do
- {
- }
- while (window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] &&
- window[++scan] == window[++match] && scan < strend);
- len = MAX_MATCH - (strend - scan);
- scan = strend - MAX_MATCH;
- if (len > best_len)
- {
- match_start = cur_match;
- best_len = len;
- if (len >= niceLength)
- {
- break;
- }
- scan_end1 = window[scan + best_len - 1];
- scan_end = window[scan + best_len];
- }
- }
- while ((cur_match = (prev[cur_match & wmask] & 0xffff)) > limit && --chain_length != 0);
- if (best_len <= lookahead)
- {
- return best_len;
- }
- return lookahead;
- }
- private bool Rfc1950BytesEmitted;
- internal bool WantRfc1950HeaderBytes { get; set; } = true;
- internal int Initialize(ZlibCodec codec, CompressionLevel level)
- {
- return Initialize(codec, level, ZlibConstants.WindowBitsMax);
- }
- internal int Initialize(ZlibCodec codec, CompressionLevel level, int bits)
- {
- return Initialize(codec, level, bits, MEM_LEVEL_DEFAULT, CompressionStrategy.Default);
- }
- internal int Initialize(ZlibCodec codec, CompressionLevel level, int bits,
- CompressionStrategy compressionStrategy)
- {
- return Initialize(codec, level, bits, MEM_LEVEL_DEFAULT, compressionStrategy);
- }
- internal int Initialize(ZlibCodec codec, CompressionLevel level, int windowBits, int memLevel,
- CompressionStrategy strategy)
- {
- _codec = codec;
- _codec.Message = null;
-
- if (windowBits < 9 || windowBits > 15)
- {
- throw new ZlibException("windowBits must be in the range 9..15.");
- }
- if (memLevel < 1 || memLevel > MEM_LEVEL_MAX)
- {
- throw new ZlibException(String.Format("memLevel must be in the range 1.. {0}", MEM_LEVEL_MAX));
- }
- _codec.dstate = this;
- w_bits = windowBits;
- w_size = 1 << w_bits;
- w_mask = w_size - 1;
- hash_bits = memLevel + 7;
- hash_size = 1 << hash_bits;
- hash_mask = hash_size - 1;
- hash_shift = ((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
- window = new byte[w_size * 2];
- prev = new short[w_size];
- head = new short[hash_size];
-
- lit_bufsize = 1 << (memLevel + 6);
-
-
-
-
- pending = new byte[lit_bufsize * 4];
- _distanceOffset = lit_bufsize;
- _lengthOffset = (1 + 2) * lit_bufsize;
-
-
-
-
- compressionLevel = level;
- compressionStrategy = strategy;
- Reset();
- return ZlibConstants.Z_OK;
- }
- internal void Reset()
- {
- _codec.TotalBytesIn = _codec.TotalBytesOut = 0;
- _codec.Message = null;
-
- pendingCount = 0;
- nextPending = 0;
- Rfc1950BytesEmitted = false;
- status = (WantRfc1950HeaderBytes) ? INIT_STATE : BUSY_STATE;
- _codec._Adler32 = Adler.Adler32(0, null, 0, 0);
- last_flush = (int)FlushType.None;
- _InitializeTreeData();
- _InitializeLazyMatch();
- }
- internal int End()
- {
- if (status != INIT_STATE && status != BUSY_STATE && status != FINISH_STATE)
- {
- return ZlibConstants.Z_STREAM_ERROR;
- }
-
- pending = null;
- head = null;
- prev = null;
- window = null;
-
-
- return status == BUSY_STATE ? ZlibConstants.Z_DATA_ERROR : ZlibConstants.Z_OK;
- }
- private void SetDeflater()
- {
- switch (config.Flavor)
- {
- case DeflateFlavor.Store:
- DeflateFunction = DeflateNone;
- break;
- case DeflateFlavor.Fast:
- DeflateFunction = DeflateFast;
- break;
- case DeflateFlavor.Slow:
- DeflateFunction = DeflateSlow;
- break;
- }
- }
- internal int SetParams(CompressionLevel level, CompressionStrategy strategy)
- {
- int result = ZlibConstants.Z_OK;
- if (compressionLevel != level)
- {
- Config newConfig = Config.Lookup(level);
-
- if (newConfig.Flavor != config.Flavor && _codec.TotalBytesIn != 0)
- {
-
- result = _codec.Deflate(FlushType.Partial);
- }
- compressionLevel = level;
- config = newConfig;
- SetDeflater();
- }
-
- compressionStrategy = strategy;
- return result;
- }
- internal int SetDictionary(byte[] dictionary)
- {
- int length = dictionary.Length;
- int index = 0;
- if (dictionary == null || status != INIT_STATE)
- {
- throw new ZlibException("Stream error.");
- }
- _codec._Adler32 = Adler.Adler32(_codec._Adler32, dictionary, 0, dictionary.Length);
- if (length < MIN_MATCH)
- {
- return ZlibConstants.Z_OK;
- }
- if (length > w_size - MIN_LOOKAHEAD)
- {
- length = w_size - MIN_LOOKAHEAD;
- index = dictionary.Length - length;
- }
- Array.Copy(dictionary, index, window, 0, length);
- strstart = length;
- blockStart = length;
-
-
-
- ins_h = window[0] & 0xff;
- ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
- for (int n = 0; n <= length - MIN_MATCH; n++)
- {
- ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
- prev[n & w_mask] = head[ins_h];
- head[ins_h] = (short)n;
- }
- return ZlibConstants.Z_OK;
- }
- internal int Deflate(FlushType flush)
- {
- int old_flush;
- if (_codec.OutputBuffer == null ||
- (_codec.InputBuffer == null && _codec.AvailableBytesIn != 0) ||
- (status == FINISH_STATE && flush != FlushType.Finish))
- {
- _codec.Message = _ErrorMessage[ZlibConstants.Z_NEED_DICT - (ZlibConstants.Z_STREAM_ERROR)];
- throw new ZlibException(String.Format("Something is fishy. [{0}]", _codec.Message));
-
- }
- if (_codec.AvailableBytesOut == 0)
- {
- _codec.Message = _ErrorMessage[ZlibConstants.Z_NEED_DICT - (ZlibConstants.Z_BUF_ERROR)];
- throw new ZlibException("OutputBuffer is full (AvailableBytesOut == 0)");
-
- }
- old_flush = last_flush;
- last_flush = (int)flush;
-
- if (status == INIT_STATE)
- {
- int header = (Z_DEFLATED + ((w_bits - 8) << 4)) << 8;
- int level_flags = (((int)compressionLevel - 1) & 0xff) >> 1;
- if (level_flags > 3)
- {
- level_flags = 3;
- }
- header |= (level_flags << 6);
- if (strstart != 0)
- {
- header |= PRESET_DICT;
- }
- header += 31 - (header % 31);
- status = BUSY_STATE;
-
- unchecked
- {
- pending[pendingCount++] = (byte)(header >> 8);
- pending[pendingCount++] = (byte)header;
- }
-
- if (strstart != 0)
- {
-
-
-
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0xFF000000) >> 24);
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0x00FF0000) >> 16);
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0x0000FF00) >> 8);
- pending[pendingCount++] = (byte)(_codec._Adler32 & 0x000000FF);
- }
- _codec._Adler32 = Adler.Adler32(0, null, 0, 0);
- }
-
- if (pendingCount != 0)
- {
- _codec.flush_pending();
- if (_codec.AvailableBytesOut == 0)
- {
-
-
-
-
-
-
- last_flush = -1;
- return ZlibConstants.Z_OK;
- }
-
-
-
- }
- else if (_codec.AvailableBytesIn == 0 &&
- (int)flush <= old_flush &&
- flush != FlushType.Finish)
- {
-
-
-
-
-
-
-
- return ZlibConstants.Z_OK;
- }
-
- if (status == FINISH_STATE && _codec.AvailableBytesIn != 0)
- {
- _codec.Message = _ErrorMessage[ZlibConstants.Z_NEED_DICT - (ZlibConstants.Z_BUF_ERROR)];
- throw new ZlibException("status == FINISH_STATE && _codec.AvailableBytesIn != 0");
- }
-
- if (_codec.AvailableBytesIn != 0 || lookahead != 0 || (flush != FlushType.None && status != FINISH_STATE))
- {
- BlockState bstate = DeflateFunction(flush);
- if (bstate == BlockState.FinishStarted || bstate == BlockState.FinishDone)
- {
- status = FINISH_STATE;
- }
- if (bstate == BlockState.NeedMore || bstate == BlockState.FinishStarted)
- {
- if (_codec.AvailableBytesOut == 0)
- {
- last_flush = -1;
- }
- return ZlibConstants.Z_OK;
-
-
-
-
-
-
- }
- if (bstate == BlockState.BlockDone)
- {
- if (flush == FlushType.Partial)
- {
- _tr_align();
- }
- else
- {
-
- _tr_stored_block(0, 0, false);
-
-
- if (flush == FlushType.Full)
- {
-
- for (int i = 0; i < hash_size; i++)
- {
- head[i] = 0;
- }
- }
- }
- _codec.flush_pending();
- if (_codec.AvailableBytesOut == 0)
- {
- last_flush = -1;
- return ZlibConstants.Z_OK;
- }
- }
- }
- if (flush != FlushType.Finish)
- {
- return ZlibConstants.Z_OK;
- }
- if (!WantRfc1950HeaderBytes || Rfc1950BytesEmitted)
- {
- return ZlibConstants.Z_STREAM_END;
- }
-
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0xFF000000) >> 24);
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0x00FF0000) >> 16);
- pending[pendingCount++] = (byte)((_codec._Adler32 & 0x0000FF00) >> 8);
- pending[pendingCount++] = (byte)(_codec._Adler32 & 0x000000FF);
-
-
- _codec.flush_pending();
-
-
- Rfc1950BytesEmitted = true;
- return pendingCount != 0 ? ZlibConstants.Z_OK : ZlibConstants.Z_STREAM_END;
- }
- }
- }
|