protected static void hbMakeCodeLengths()

in lib-src/bzip2/org/apache/tools/bzip2r/CBZip2OutputStream.java [132:277]
131 lines of code
26 McCabe index (conditional complexity)

    protected static void hbMakeCodeLengths(char[] len, int[] freq,
                                            int alphaSize, int maxLen) {
        /*
          Nodes and heap entries run from 1.  Entry 0
          for both the heap and nodes is a sentinel.
        */
        int nNodes, nHeap, n1, n2, i, j, k;
        boolean  tooLong;

        int[] heap = new int[MAX_ALPHA_SIZE + 2];
        int[] weight = new int[MAX_ALPHA_SIZE * 2];
        int[] parent = new int[MAX_ALPHA_SIZE * 2];

        for (i = 0; i < alphaSize; i++) {
            weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8;
        }

        while (true) {
            nNodes = alphaSize;
            nHeap = 0;

            heap[0] = 0;
            weight[0] = 0;
            parent[0] = -2;

            for (i = 1; i <= alphaSize; i++) {
                parent[i] = -1;
                nHeap++;
                heap[nHeap] = i;
                {
                    int zz, tmp;
                    zz = nHeap;
                    tmp = heap[zz];
                    while (weight[tmp] < weight[heap[zz >> 1]]) {
                        heap[zz] = heap[zz >> 1];
                        zz >>= 1;
                    }
                    heap[zz] = tmp;
                }
            }
            if (!(nHeap < (MAX_ALPHA_SIZE + 2))) {
                panic();
            }

            while (nHeap > 1) {
                n1 = heap[1];
                heap[1] = heap[nHeap];
                nHeap--;
                {
                    int zz = 0, yy = 0, tmp = 0;
                    zz = 1;
                    tmp = heap[zz];
                    while (true) {
                        yy = zz << 1;
                        if (yy > nHeap) {
                            break;
                        }
                        if (yy < nHeap
                            && weight[heap[yy + 1]] < weight[heap[yy]]) {
                            yy++;
                        }
                        if (weight[tmp] < weight[heap[yy]]) {
                            break;
                        }
                        heap[zz] = heap[yy];
                        zz = yy;
                    }
                    heap[zz] = tmp;
                }
                n2 = heap[1];
                heap[1] = heap[nHeap];
                nHeap--;
                {
                    int zz = 0, yy = 0, tmp = 0;
                    zz = 1;
                    tmp = heap[zz];
                    while (true) {
                        yy = zz << 1;
                        if (yy > nHeap) {
                            break;
                        }
                        if (yy < nHeap
                            && weight[heap[yy + 1]] < weight[heap[yy]]) {
                            yy++;
                        }
                        if (weight[tmp] < weight[heap[yy]]) {
                            break;
                        }
                        heap[zz] = heap[yy];
                        zz = yy;
                    }
                    heap[zz] = tmp;
                }
                nNodes++;
                parent[n1] = parent[n2] = nNodes;

                weight[nNodes] = ((weight[n1] & 0xffffff00)
                                  + (weight[n2] & 0xffffff00))
                    | (1 + (((weight[n1] & 0x000000ff) >
                             (weight[n2] & 0x000000ff)) ?
                            (weight[n1] & 0x000000ff) :
                            (weight[n2] & 0x000000ff)));

                parent[nNodes] = -1;
                nHeap++;
                heap[nHeap] = nNodes;
                {
                    int zz = 0, tmp = 0;
                    zz = nHeap;
                    tmp = heap[zz];
                    while (weight[tmp] < weight[heap[zz >> 1]]) {
                        heap[zz] = heap[zz >> 1];
                        zz >>= 1;
                    }
                    heap[zz] = tmp;
                }
            }
            if (!(nNodes < (MAX_ALPHA_SIZE * 2))) {
                panic();
            }

            tooLong = false;
            for (i = 1; i <= alphaSize; i++) {
                j = 0;
                k = i;
                while (parent[k] >= 0) {
                    k = parent[k];
                    j++;
                }
                len[i - 1] = (char) j;
                if (j > maxLen) {
                    tooLong = true;
                }
            }

            if (!tooLong) {
                break;
            }

            for (i = 1; i < alphaSize; i++) {
                j = weight[i] >> 8;
                j = 1 + (j / 2);
                weight[i] = j << 8;
            }
        }
    }