public int deflateEnd() {
if (this.dstate == null) {
return -2;
}
int num = this.dstate.deflateEnd();
this.dstate = null;
return num;
}
public override void OnActionExecuting(HttpActionContext actionContext)
{
var content = actionContext.Request.Content;
var zipContentBytes = content == null ? null : content.ReadAsByteArrayAsync().Result;
var unzipContentBytes = zipContentBytes == null ? new byte[0] : Deflate.Decompress(zipContentBytes);
actionContext.Request.Content = new ByteArrayContent(unzipContentBytes);
base.OnActionExecuting(actionContext);
}
public static MutableString /*!*/ Flush(Deflate /*!*/ self, [DefaultParameterValue(SYNC_FLUSH)] int flush)
{
if (flush == NO_FLUSH)
{
return(MutableString.CreateEmpty());
}
return(Compress(self, MutableString.FrozenEmpty, flush));
}
public static async Task <byte[]> DecompressAsync(ReadOnlyMemory <byte> data, CompressionMethod method)
{
return(method switch
{
CompressionMethod.LZ4 => await LZ4.DecompressAsync(data).ConfigureAwait(false),
CompressionMethod.Deflate => await Deflate.DecompressAsync(data).ConfigureAwait(false),
CompressionMethod.Brotli => await Brotli.DecompressAsync(data).ConfigureAwait(false),
CompressionMethod.Gzip => await Gzip.DecompressAsync(data).ConfigureAwait(false),
_ => await Gzip.DecompressAsync(data).ConfigureAwait(false)
});
internal int DeflateEnd()
{
if (dstate == null)
{
return(Z_STREAM_ERROR);
}
int ret = dstate.DeflateEnd();
dstate = null;
return(ret);
}
public int DeflateEnd()
{
if (Dstate == null)
{
return(ZStreamError);
}
int ret = Dstate.DeflateEnd();
Dstate = null;
return(ret);
}
public int deflateEnd()
{
if (dstate == null)
{
return(Z_STREAM_ERROR);
}
int ret = dstate.deflateEnd();
dstate = null;
return(ret);
}
public int deflateEnd()
{
if (dstate == null)
{
return(-2);
}
int result = dstate.deflateEnd();
dstate = null;
return(result);
}
public static void SetParams(Deflate /*!*/ self, [NotNull] MutableString /*!*/ dictionary)
{
byte[] buffer = dictionary.ToByteArray();
var zst = self.GetStream();
int err = zst.deflateSetDictionary(buffer, buffer.Length);
if (err != Z_OK)
{
throw MakeError(err, zst.msg);
}
}
public static void SetParams(
Deflate /*!*/ self,
[DefaultParameterValue(DEFAULT_COMPRESSION)] int level,
[DefaultParameterValue(DEFAULT_STRATEGY)] int strategy)
{
var zst = self.GetStream();
int err = zst.deflateParams(level, (zlib.CompressionStrategy)strategy);
if (err != Z_OK)
{
throw MakeError(err, zst.msg);
}
}
public void Server_DeflateCompress_Client_DeflateDecompress_should_be_yao()
{
Console.WriteLine("用戶端用訪問伺服器→伺服器用Deflate壓縮資料→Client解壓縮，驗證解壓縮結果是否包含關鍵字");
var url = "api/test/DeflateCompression/yao";
var response = MsTestHook.Client.GetAsync(url).Result;
var content = response.Content.ReadAsByteArrayAsync().Result;
var decompress = Deflate.Decompress(content);
var result = Encoding.UTF8.GetString(decompress);
Assert.AreEqual(response.StatusCode, HttpStatusCode.OK);
Assert.AreEqual(true, result.Contains("yao"));
}
protected void Write(Stream stream, SocketMessager messager)
{
MemoryStream ms = new MemoryStream();
byte[] buff = Encoding.UTF8.GetBytes(messager.GetCanParseString());
ms.Write(buff, 0, buff.Length);
if (messager.Arg != null)
{
buff = Deflate.Compress(BaseSocket.Serialize(messager.Arg));
ms.Write(buff, 0, buff.Length);
}
this.Write(stream, ms.ToArray());
ms.Close();
}
/// <summary>
/// All dynamically allocated data structures for this stream are freed. This function discards any unprocessed input and does not flush any pending
/// output.
/// </summary>
/// <returns>
/// deflateEnd returns <see cref="ZLibResultCode.Z_OK" /> if success, <see cref="ZLibResultCode.Z_STREAM_ERROR" /> if the stream state was inconsistent,
/// <see cref="ZLibResultCode.Z_DATA_ERROR" /> if the stream was freed prematurely (some input or output was discarded). In the error case,
/// <see cref="msg" /> may be set but then points to a static string (which must not be deallocated).
/// </returns>
public int deflateEnd()
{
next_in_index = 0;
next_out_index = 0;
if (_dstate == null)
{
return((int)ZLibResultCode.Z_STREAM_ERROR);
}
int ret = _dstate.deflateEnd();
_dstate = null;
return(ret);
}
public static Deflate /*!*/ AppendData(Deflate /*!*/ self, [DefaultProtocol] MutableString str)
{
var zst = self.GetStream();
MutableString trailingUncompressedData = null;
int result = Process(zst, str, zlib.FlushStrategy.Z_NO_FLUSH, compress, ref trailingUncompressedData);
if (result != Z_OK)
{
throw MakeError(result, zst.msg);
}
return(self);
}
public override void OnActionExecuted(HttpActionExecutedContext actionContext)
{
var content = actionContext.Response.Content;
var sourceBytes = content == null ? null : content.ReadAsByteArrayAsync().Result;
var zipContent = sourceBytes == null ? new byte[0] : Deflate.Compress(sourceBytes);
actionContext.Response.Content = new ByteArrayContent(zipContent);
actionContext.Response.Content.Headers.Remove("Content-Type");
actionContext.Response.Content.Headers.Add("Content-encoding", "deflate");
//actContext.Response.Content.Headers.Add("Content-Type", "application/json");
actionContext.Response.Content.Headers.Add("Content-Type", "application/json;charset=utf-8");
base.OnActionExecuted(actionContext);
}
public static MutableString /*!*/ Compress(Deflate /*!*/ self, [DefaultProtocol] MutableString str, [DefaultParameterValue(NO_FLUSH)] int flush)
{
MutableString compressed;
MutableString trailingUncompressedData = null;
var zst = self.GetStream();
int result = Process(zst, str, (zlib.FlushStrategy)flush, compress, out compressed, ref trailingUncompressedData);
if (result != Z_OK)
{
throw MakeError(result, zst.msg);
}
return(compressed);
}
public void RoundTripListObject()
{
List <int> start = new List <int> {
1, 3, 4
};
string startString = JsonConvert.SerializeObject(start);
byte[] encoded = Deflate.Encode(startString);
byte[] finishBytes = Deflate.Decode(encoded);
string finishString = Encoding.UTF8.GetString(finishBytes);
List <int> finish = JsonConvert.DeserializeObject <List <int> >(finishString);
Assert.Equal(start, finish);
}
public void Client_DeflateCompress_Server_DeflateDecompress()
{
Console.WriteLine("用戶端用Deflate壓縮資料→伺服器端解壓縮後回傳結果→驗證解壓縮結果和Client壓縮前是否相同");
var url = "api/test/DeflateDecompression";
var builder = CreateData();
var contentBytes = Encoding.UTF8.GetBytes(builder);
var zipContent = Deflate.Compress(contentBytes);
var request = new HttpRequestMessage(HttpMethod.Post, url)
{
Content = new ByteArrayContent(zipContent)
};
var response = MsTestHook.Client.SendAsync(request).Result;
var result = response.Content.ReadAsStringAsync().Result;
Assert.AreEqual(response.StatusCode, HttpStatusCode.OK);
Assert.AreEqual(builder, result);
}
private static Dictionary <string, MapcacheMapData> ReadMapcache(string path)
{
Dictionary <string, MapcacheMapData> mapdata = new Dictionary <string, MapcacheMapData>();
byte[] decodedBuf, encodedBuf;
// We want a relative path
if (path[0] == '/' || path[0] == '\\')
{
path = path.Substring(1);
}
//path = Path.Combine(Core.Conf.ConfigDir, path);
using (FileStream fs = File.OpenRead(path)) {
using (BinaryReader bin = new BinaryReader(fs)) {
uint mapCount = bin.ReadUInt32();
for (int i = 0; i < mapCount; i++)
{
// Mapinfo
string mapname = bin.ReadString();
short xs = bin.ReadInt16();
short ys = bin.ReadInt16();
int len = bin.ReadInt32();
encodedBuf = bin.ReadBytes(len);
decodedBuf = Deflate.Decompress(encodedBuf);
// encodedBuf now contains the cell array
mapdata.Add(mapname, new MapcacheMapData {
Width = xs,
Height = ys,
CellData = decodedBuf
});
encodedBuf = null;
decodedBuf = null;
}
}
}
return(mapdata);
}
/* Utility method */
// 'input' is a string of 0's and 1's (with optional spaces) representing the input bit sequence.
// 'refOutput' is a string of pairs of hexadecimal digits (with optional spaces) representing
// the expected decompressed output byte sequence.
private static void test(string input, string refOutput)
{
refOutput = refOutput.Replace(" ", string.Empty);
if (refOutput.Length % 2 != 0)
{
throw new ArgumentException();
}
var refOut = new byte[refOutput.Length / 2];
for (int i = 0; i < refOut.Length; i++)
{
refOut[i] = (byte)int.Parse(refOutput.Substring(i * 2, 2), NumberStyles.HexNumber);
}
input = input.Replace(" ", string.Empty);
var inputStream = new StringBitReader(input);
byte[] actualOut = Deflate.Decompress(inputStream);
AssertArrayEquals(refOut, actualOut);
}
/// <summary>
/// Returns the file data, decompressed if needed
/// </summary>
/// <param name="item">The grf file</param>
/// <param name="decompress">Should the data decompressed?</param>
/// <returns></returns>
public byte[] GetFileData(FileItem item, bool decompress)
{
byte[] buf = null;
bool isUpdated = item.IsAdded || item.IsUpdated;
if (isUpdated)
{
// Load data from file
buf = File.ReadAllBytes(item.NewFilepath);
}
else if (item.FileData == null || item.FileData.Length != item.LengthCompressedAlign)
{
// Cache data
CacheFileData(item);
buf = item.FileData;
}
else
{
buf = item.FileData;
}
if (isUpdated == false && buf != null && buf.Length > 0)
{
// deocde, if needed
if (item.Cycle >= 0 && Deflate.IsMagicHead(buf) == false)
{
EncryptionHelper.DecryptFileData(buf, item.Cycle == 0, item.Cycle);
}
// Decompress data
if (decompress)
{
buf = Deflate.Decompress(buf);
}
}
return(buf);
}
static void Deflatetest()
{
BufferFormat fan = new BufferFormat(1000, new FDataExtraHandle((o) =>
{
return(Deflate.Compress(o));
}));
fan.AddItem(true);
fan.AddItem("abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc");
fan.AddItem(123);
byte[] data = fan.Finish();
ReadBytes read = new ReadBytes(data, 4, -1, new RDataExtraHandle((o) =>
{
return(Deflate.Decompress(o));
}));
int lengt;
int cmd;
bool var1;
string var2;
int var3;
if (read.IsDataExtraSuccess &&
read.ReadInt32(out lengt) &&
lengt == read.Length &&
read.ReadInt32(out cmd) &&
read.ReadBoolean(out var1) &&
read.ReadString(out var2) &&
read.ReadInt32(out var3))
{
Console.WriteLine("压缩前长度:{0}", read.Data.Length);
Console.WriteLine("压缩后长度:{0}", read.Length);
Console.WriteLine("This Deflate-> Length:{0} Cmd:{1} var1:{2} var2:{3} var3:{4}", lengt, cmd, var1, var2, var3);
}
}
public int deflateInit(int level, int bits, bool nowrap)
{
dstate = new Deflate();
return(dstate.deflateInit(this, level, nowrap?-bits:bits));
}
public int deflateInit(int level, int bits)
{
dstate = new Deflate();
return dstate.deflateInit(this, level, bits);
}
public int deflateEnd()
{
if (dstate == null)
return Z_STREAM_ERROR;
int ret = dstate.deflateEnd();
dstate = null;
return ret;
}
internal int DeflateInit(int level, int bits, bool nowrap)
{
dstate = new Deflate(this);
return(dstate.DeflateInit(level, nowrap ? -bits : bits));
}
internal int DeflateInit(int level, int bits, int memlevel)
{
dstate = new Deflate(this);
return(dstate.DeflateInit(level, bits, memlevel));
}
private void btnBuild_Click(object sender, EventArgs e)
{
if (this._tables.Find(delegate(TableInfo table) {
return(table.IsOutput);
}) == null)
{
DataGridViewCellMouseEventArgs e2 = new DataGridViewCellMouseEventArgs(1, -1, 1, 1, new MouseEventArgs(MouseButtons.Left, 1, 1, 1, 1));
this.dgvGridview_ColumnHeaderMouseClick(this, e2);
}
FolderBrowserDialog fbd = new FolderBrowserDialog();
if (fbd.ShowDialog() != DialogResult.OK)
{
return;
}
string selectedPath = fbd.SelectedPath;
List <BuildInfo> bs = null;
SocketMessager messager = new SocketMessager("Build", new object[] {
this.txtSolution.Text,
this.chkSolution.Checked,
string.Join("", this._tables.ConvertAll <string>(delegate(TableInfo table){
return(string.Concat(table.IsOutput ? 1 : 0));
}).ToArray()),
this.chkWebAdmin.Checked,
this.chkDownloadRes.Checked
});
this._socket.Write(messager, delegate(object sender2, ClientSocketReceiveEventArgs e2) {
bs = e2.Messager.Arg as List <BuildInfo>;
if (e2.Messager.Arg is Exception)
{
throw e2.Messager.Arg as Exception;
}
}, TimeSpan.FromSeconds(60 * 5));
if (bs == null)
{
return;
}
foreach (BuildInfo b in bs)
{
string path = Path.Combine(selectedPath, b.Path);
Directory.CreateDirectory(Path.GetDirectoryName(path));
string fileName = Path.GetFileName(b.Path);
string ext = Path.GetExtension(b.Path);
Encoding encode = Encoding.UTF8;
if (fileName.EndsWith(".rar") || fileName.EndsWith(".zip") || fileName.EndsWith(".dll"))
{
using (FileStream fs = new FileStream(path, FileMode.Create, FileAccess.Write)) {
fs.Write(b.Data, 0, b.Data.Length);
fs.Close();
}
continue;
}
byte[] data = Deflate.Decompress(b.Data);
string content = Encoding.UTF8.GetString(data);
if (string.Compare(fileName, "web.config") == 0)
{
string place = System.Web.HttpUtility.HtmlEncode(this.ConnectionString);
content = content.Replace("{connectionString}", place);
}
//if (string.Compare(fileName, "procedure.sql") == 0) {
// this.ExecuteNonQuery(content);
//}
if (string.Compare(ext, ".refresh") == 0)
{
encode = Encoding.Unicode;
}
using (StreamWriter sw = new StreamWriter(path, false, encode)) {
sw.Write(content);
sw.Close();
}
}
GC.Collect();
Lib.Msgbox("The code files be maked in \"" + selectedPath + "\", please check.");
//System.Diagnostics.Process.Start("iexplore.exe", "http://www.penzz.com/");
}
public int DeflateInit(int level, int bits)
{
dstate = new Deflate();
return(dstate.deflateInit(this, level, bits));
}
// Construct one Huffman tree and assigns the code bit strings and lengths.
// Update the total bit length for the current block.
// IN assertion: the field freq is set for all tree elements.
// OUT assertions: the fields len and code are set to the optimal bit length
// and corresponding code. The length opt_len is updated; static_len is
// also updated if stree is not null. The field max_code is set.
internal void Build_tree(Deflate s)
{
short[] tree = dyn_tree;
short[] stree = stat_desc.static_tree;
int elems = stat_desc.elems;
int n, m; // iterate over heap elements
int max_code = -1; // largest code with non zero frequency
int node; // new node being created
// Construct the initial heap, with least frequent element in
// heap[1]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
// heap[0] is not used.
s.heap_len = 0;
s.heap_max = HEAP_SIZE;
for (n = 0; n < elems; n++)
{
if (tree[n * 2] != 0)
{
s.heap[++s.heap_len] = max_code = n;
s.depth[n] = 0;
}
else
{
tree[n * 2 + 1] = 0;
}
}
// The pkzip format requires that at least one distance code exists,
// and that at least one bit should be sent even if there is only one
// possible code. So to avoid special checks later on we force at least
// two codes of non zero frequency.
while (s.heap_len < 2)
{
node = s.heap[++s.heap_len] = (max_code < 2 ? ++max_code : 0);
tree[node * 2] = 1;
s.depth[node] = 0;
s.opt_len--;
if (stree is object)
{
s.static_len -= stree[node * 2 + 1];
}
// node is 0 or 1 so it does not have extra bits
}
this.max_code = max_code;
// The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
// establish sub-heaps of increasing lengths:
for (n = s.heap_len / 2; n >= 1; n--)
{
s.Pqdownheap(tree, n);
}
// Construct the Huffman tree by repeatedly combining the least two
// frequent nodes.
node = elems; // next internal node of the tree
do
{
// n = node of least frequency
n = s.heap[1];
s.heap[1] = s.heap[s.heap_len--];
s.Pqdownheap(tree, 1);
m = s.heap[1]; // m = node of next least frequency
s.heap[--s.heap_max] = n; // keep the nodes sorted by frequency
s.heap[--s.heap_max] = m;
// Create a new node father of n and m
tree[node * 2] = (short)(tree[n * 2] + tree[m * 2]);
s.depth[node] = (byte)(Math.Max(s.depth[n], s.depth[m]) + 1);
tree[n * 2 + 1] = tree[m * 2 + 1] = (short)node;
// and insert the new node in the heap
s.heap[1] = node++;
s.Pqdownheap(tree, 1);
}while (s.heap_len >= 2);
s.heap[--s.heap_max] = s.heap[1];
// At this point, the fields freq and dad are set. We can now
// generate the bit lengths.
this.Gen_bitlen(s);
// The field len is now set, we can generate the bit codes
Gen_codes(tree, max_code, s.bl_count, s.next_code);
}
public int DeflateInit(int level, int windowBits, int memLevel, CompressionStrategy strategy)
{
_dstate = new Deflate();
return(_dstate.DeflateInit2(this, level, windowBits, memLevel, strategy));
}
internal StaticTree stat_desc; // the corresponding static tree
// Compute the optimal bit lengths for a tree and update the total bit length
// for the current block.
// IN assertion: the fields freq and dad are set, heap[heap_max] and
// above are the tree nodes sorted by increasing frequency.
// OUT assertions: the field len is set to the optimal bit length, the
// array bl_count contains the frequencies for each bit length.
// The length opt_len is updated; static_len is also updated if stree is
// not null.
void Gen_bitlen(Deflate s)
{
short[] tree = dyn_tree;
short[] stree = stat_desc.static_tree;
int[] extra = stat_desc.extra_bits;
int _base = stat_desc.extra_base;
int max_length = stat_desc.max_length;
int h; // heap index
int n, m; // iterate over the tree elements
int bits; // bit length
int xbits; // extra bits
short f; // frequency
int overflow = 0; // number of elements with bit length too large
for (bits = 0; bits <= MAX_BITS; bits++)
{
s.bl_count[bits] = 0;
}
// In a first pass, compute the optimal bit lengths (which may
// overflow in the case of the bit length tree).
tree[s.heap[s.heap_max] * 2 + 1] = 0; // root of the heap
for (h = s.heap_max + 1; h < HEAP_SIZE; h++)
{
n = s.heap[h];
bits = tree[tree[n * 2 + 1] * 2 + 1] + 1;
if (bits > max_length)
{
bits = max_length;
overflow++;
}
tree[n * 2 + 1] = (short)bits;
// We overwrite tree[n*2+1] which is no longer needed
if (n > max_code)
{
continue; // not a leaf node
}
s.bl_count[bits]++;
xbits = 0;
if (n >= _base)
{
xbits = extra[n - _base];
}
f = tree[n * 2];
s.opt_len += f * (bits + xbits);
if (stree is object)
{
s.static_len += f * (stree[n * 2 + 1] + xbits);
}
}
if (overflow == 0)
{
return;
}
// This happens for example on obj2 and pic of the Calgary corpus
// Find the first bit length which could increase:
do
{
bits = max_length - 1;
while (s.bl_count[bits] == 0)
{
bits--;
}
s.bl_count[bits]--; // move one leaf down the tree
s.bl_count[bits + 1] += 2; // move one overflow item as its brother
s.bl_count[max_length]--;
// The brother of the overflow item also moves one step up,
// but this does not affect bl_count[max_length]
overflow -= 2;
}while (overflow > 0);
for (bits = max_length; bits != 0; bits--)
{
n = s.bl_count[bits];
while (n != 0)
{
m = s.heap[--h];
if (m > max_code)
{
continue;
}
if (tree[m * 2 + 1] != bits)
{
s.opt_len += (int)(((long)bits - (long)tree[m * 2 + 1]) * (long)tree[m * 2]);
tree[m * 2 + 1] = (short)bits;
}
n--;
}
}
}
internal StaticTree stat_desc; // the corresponding static tree
// Compute the optimal bit lengths for a tree and update the total bit length
// for the current block.
// IN assertion: the fields freq and dad are set, heap[heap_max] and
// above are the tree nodes sorted by increasing frequency.
// OUT assertions: the field len is set to the optimal bit length, the
// array bl_count contains the frequencies for each bit length.
// The length opt_len is updated; static_len is also updated if stree is
// not null.
internal void gen_bitlen(Deflate s)
{
short[] tree = dyn_tree;
short[] stree = stat_desc.static_tree;
int[] extra = stat_desc.extra_bits;
int base_Renamed = stat_desc.extra_base;
int max_length = stat_desc.max_length;
int h; // heap index
int n, m; // iterate over the tree elements
int bits; // bit length
int xbits; // extra bits
short f; // frequency
int overflow = 0; // number of elements with bit length too large
for (bits = 0; bits <= MAX_BITS; bits++)
s.bl_count[bits] = 0;
// In a first pass, compute the optimal bit lengths (which may
// overflow in the case of the bit length tree).
tree[s.heap[s.heap_max] * 2 + 1] = 0; // root of the heap
for (h = s.heap_max + 1; h < HEAP_SIZE; h++)
{
n = s.heap[h];
bits = tree[tree[n * 2 + 1] * 2 + 1] + 1;
if (bits > max_length)
{
bits = max_length; overflow++;
}
tree[n * 2 + 1] = (short) bits;
// We overwrite tree[n*2+1] which is no longer needed
if (n > max_code)
continue; // not a leaf node
s.bl_count[bits]++;
xbits = 0;
if (n >= base_Renamed)
xbits = extra[n - base_Renamed];
f = tree[n * 2];
s.opt_len += f * (bits + xbits);
if (stree != null)
s.static_len += f * (stree[n * 2 + 1] + xbits);
}
if (overflow == 0)
return ;
// This happens for example on obj2 and pic of the Calgary corpus
// Find the first bit length which could increase:
do
{
bits = max_length - 1;
while (s.bl_count[bits] == 0)
bits--;
s.bl_count[bits]--; // move one leaf down the tree
s.bl_count[bits + 1] = (short) (s.bl_count[bits + 1] + 2); // move one overflow item as its brother
s.bl_count[max_length]--;
// The brother of the overflow item also moves one step up,
// but this does not affect bl_count[max_length]
overflow -= 2;
}
while (overflow > 0);
for (bits = max_length; bits != 0; bits--)
{
n = s.bl_count[bits];
while (n != 0)
{
m = s.heap[--h];
if (m > max_code)
continue;
if (tree[m * 2 + 1] != bits)
{
s.opt_len = (int) (s.opt_len + ((long) bits - (long) tree[m * 2 + 1]) * (long) tree[m * 2]);
tree[m * 2 + 1] = (short) bits;
}
n--;
}
}
}
public byte[] Serialize(object obj)
{
string stringObj = JsonConvert.SerializeObject(obj);
return(Deflate.Encode(stringObj));
}
// Construct one Huffman tree and assigns the code bit strings and lengths.
// Update the total bit length for the current block.
// IN assertion: the field freq is set for all tree elements.
// OUT assertions: the fields len and code are set to the optimal bit length
// and corresponding code. The length opt_len is updated; static_len is
// also updated if stree is not null. The field max_code is set.
internal void build_tree(Deflate s)
{
short[] tree = dyn_tree;
short[] stree = stat_desc.static_tree;
int elems = stat_desc.elems;
int n, m; // iterate over heap elements
int max_code = - 1; // largest code with non zero frequency
int node; // new node being created
// Construct the initial heap, with least frequent element in
// heap[1]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
// heap[0] is not used.
s.heap_len = 0;
s.heap_max = HEAP_SIZE;
for (n = 0; n < elems; n++)
{
if (tree[n * 2] != 0)
{
s.heap[++s.heap_len] = max_code = n;
s.depth[n] = 0;
}
else
{
tree[n * 2 + 1] = 0;
}
}
// The pkzip format requires that at least one distance code exists,
// and that at least one bit should be sent even if there is only one
// possible code. So to avoid special checks later on we force at least
// two codes of non zero frequency.
while (s.heap_len < 2)
{
node = s.heap[++s.heap_len] = (max_code < 2?++max_code:0);
tree[node * 2] = 1;
s.depth[node] = 0;
s.opt_len--;
if (stree != null)
s.static_len -= stree[node * 2 + 1];
// node is 0 or 1 so it does not have extra bits
}
this.max_code = max_code;
// The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
// establish sub-heaps of increasing lengths:
for (n = s.heap_len / 2; n >= 1; n--)
s.pqdownheap(tree, n);
// Construct the Huffman tree by repeatedly combining the least two
// frequent nodes.
node = elems; // next internal node of the tree
do
{
// n = node of least frequency
n = s.heap[1];
s.heap[1] = s.heap[s.heap_len--];
s.pqdownheap(tree, 1);
m = s.heap[1]; // m = node of next least frequency
s.heap[--s.heap_max] = n; // keep the nodes sorted by frequency
s.heap[--s.heap_max] = m;
// Create a new node father of n and m
tree[node * 2] = (short) (tree[n * 2] + tree[m * 2]);
s.depth[node] = (byte) (System.Math.Max((byte) s.depth[n], (byte) s.depth[m]) + 1);
tree[n * 2 + 1] = tree[m * 2 + 1] = (short) node;
// and insert the new node in the heap
s.heap[1] = node++;
s.pqdownheap(tree, 1);
}
while (s.heap_len >= 2);
s.heap[--s.heap_max] = s.heap[1];
// At this point, the fields freq and dad are set. We can now
// generate the bit lengths.
gen_bitlen(s);
// The field len is now set, we can generate the bit codes
gen_codes(tree, max_code, s.bl_count);
}