internal void build_tree(DeflateManager s)
{
short[] array = this.dyn_tree;
short[] treeCodes = this.staticTree.treeCodes;
int elems = this.staticTree.elems;
int num = -1;
s.heap_len = 0;
s.heap_max = Tree.HEAP_SIZE;
for (int i = 0; i < elems; i++)
{
if (array[i * 2] != 0)
{
num = (s.heap[++s.heap_len] = i);
s.depth[i] = 0;
}
else
{
array[i * 2 + 1] = 0;
}
}
int num2;
while (s.heap_len < 2)
{
num2 = (s.heap[++s.heap_len] = ((num >= 2) ? 0 : (++num)));
array[num2 * 2] = 1;
s.depth[num2] = 0;
s.opt_len--;
if (treeCodes != null)
{
s.static_len -= (int)treeCodes[num2 * 2 + 1];
}
}
this.max_code = num;
for (int i = s.heap_len / 2; i >= 1; i--)
{
s.pqdownheap(array, i);
}
num2 = elems;
do
{
int i = s.heap[1];
s.heap[1] = s.heap[s.heap_len--];
s.pqdownheap(array, 1);
int num3 = s.heap[1];
s.heap[--s.heap_max] = i;
s.heap[--s.heap_max] = num3;
array[num2 * 2] = array[i * 2] + array[num3 * 2];
s.depth[num2] = (sbyte)(Math.Max((byte)s.depth[i], (byte)s.depth[num3]) + 1);
array[i * 2 + 1] = (array[num3 * 2 + 1] = (short)num2);
s.heap[1] = num2++;
s.pqdownheap(array, 1);
}while (s.heap_len >= 2);
s.heap[--s.heap_max] = s.heap[1];
this.gen_bitlen(s);
Tree.gen_codes(array, num, s.bl_count);
}
public int EndDeflate()
{
if (this.dstate == null)
{
throw new ZlibException("No Deflate State!");
}
this.dstate = null;
return(0);
}
private int _InternalInitializeDeflate(bool wantRfc1950Header)
{
if (this.istate != null)
{
throw new ZlibException("You may not call InitializeDeflate() after calling InitializeInflate().");
}
this.dstate = new DeflateManager();
this.dstate.WantRfc1950HeaderBytes = wantRfc1950Header;
return(this.dstate.Initialize(this, this.CompressLevel, this.WindowBits, this.Strategy));
}
/// <summary>
/// End a deflation session.
/// </summary>
/// <remarks>
/// Call this after making a series of one or more calls to Deflate(). All buffers are flushed.
/// </remarks>
/// <returns>Z_OK if all goes well.</returns>
public int EndDeflate()
{
if (dstate == null)
{
throw new ZlibException("No Deflate State!");
}
// TODO: dinoch Tue, 03 Nov 2009 15:39 (test this)
//int ret = dstate.End();
dstate = null;
return(ZlibConstants.Z_OK); //ret;
}
internal void pqdownheap(short[] tree, int k)
{
int num = this.heap[k];
for (int i = k << 1; i <= this.heap_len; i <<= 1)
{
if (i < this.heap_len && DeflateManager._IsSmaller(tree, this.heap[i + 1], this.heap[i], this.depth))
{
i++;
}
if (DeflateManager._IsSmaller(tree, num, this.heap[i], this.depth))
{
break;
}
this.heap[k] = this.heap[i];
k = i;
}
this.heap[k] = num;
}
// 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(DeflateManager s)
{
short[] tree = dyn_tree;
short[] stree = staticTree.treeCodes;
int elems = staticTree.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] = unchecked ((short)(tree[n * 2] + tree[m * 2]));
s.depth[node] = (sbyte)(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);
}
internal StaticTree staticTree; // 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(DeflateManager s)
{
short[] tree = dyn_tree;
short[] stree = staticTree.treeCodes;
int[] extra = staticTree.extraBits;
int base_Renamed = staticTree.extraBase;
int max_length = staticTree.maxLength;
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 <= InternalConstants.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--;
}
}
}
internal void gen_bitlen(DeflateManager s)
{
short[] array = this.dyn_tree;
short[] treeCodes = this.staticTree.treeCodes;
int[] extraBits = this.staticTree.extraBits;
int extraBase = this.staticTree.extraBase;
int maxLength = this.staticTree.maxLength;
int num = 0;
for (int i = 0; i <= InternalConstants.MAX_BITS; i++)
{
s.bl_count[i] = 0;
}
array[s.heap[s.heap_max] * 2 + 1] = 0;
int j;
for (j = s.heap_max + 1; j < Tree.HEAP_SIZE; j++)
{
int num2 = s.heap[j];
int i = (int)(array[(int)(array[num2 * 2 + 1] * 2 + 1)] + 1);
if (i > maxLength)
{
i = maxLength;
num++;
}
array[num2 * 2 + 1] = (short)i;
if (num2 <= this.max_code)
{
short[] expr_DC_cp_0 = s.bl_count;
int expr_DC_cp_1 = i;
expr_DC_cp_0[expr_DC_cp_1] += 1;
int num3 = 0;
if (num2 >= extraBase)
{
num3 = extraBits[num2 - extraBase];
}
short num4 = array[num2 * 2];
s.opt_len += (int)num4 * (i + num3);
if (treeCodes != null)
{
s.static_len += (int)num4 * ((int)treeCodes[num2 * 2 + 1] + num3);
}
}
}
if (num == 0)
{
return;
}
do
{
int i = maxLength - 1;
while (s.bl_count[i] == 0)
{
i--;
}
short[] expr_179_cp_0 = s.bl_count;
int expr_179_cp_1 = i;
expr_179_cp_0[expr_179_cp_1] -= 1;
s.bl_count[i + 1] = s.bl_count[i + 1] + 2;
short[] expr_1A5_cp_0 = s.bl_count;
int expr_1A5_cp_1 = maxLength;
expr_1A5_cp_0[expr_1A5_cp_1] -= 1;
num -= 2;
}while (num > 0);
for (int i = maxLength; i != 0; i--)
{
int num2 = (int)s.bl_count[i];
while (num2 != 0)
{
int num5 = s.heap[--j];
if (num5 <= this.max_code)
{
if ((int)array[num5 * 2 + 1] != i)
{
s.opt_len = (int)((long)s.opt_len + ((long)i - (long)array[num5 * 2 + 1]) * (long)array[num5 * 2]);
array[num5 * 2 + 1] = (short)i;
}
num2--;
}
}
}
}
