void DeleteTrie(TNode * root)
{
if (!root)
return;
DeleteTrie(root->l);
DeleteTrie(root->r);
delete root;
}
void DeleteTrie(struct node *p)
{
if (p->l)
DeleteTrie(p->l);
if (p->r)
DeleteTrie(p->r);
FREE(p);
} /* DeleteTrie */
long DecodeHuffman(const void *inData, void **outData)
{
struct node *root, *n;
unsigned short *code;
unsigned char *ascii, *sp, *dp;
long i, j, l;
struct HuffmanHeader *h;
h = (struct HuffmanHeader *)inData;
h->hSourceLength = ntohl(h->hSourceLength);
h->hCompressedLength = ntohl(h->hCompressedLength);
h->hCodeCount = ntohs(h->hCodeCount);
*outData = NULL;
/* Check de header, we willen geen bogus data decoderen... */
if (h->hVersion != kVersion)
return -1;
/* pointers naar de verschillende data onderdelen */
code = (unsigned short *)((char *)inData + kHuffmanHeaderSize);
ascii = (unsigned char *)(code + h->hCodeCount);
/* Bouw de decodeer Trie, dit is een radix search trie */
root = NULL;
for (i = 0; i < h->hCodeCount; i++)
RadixInsert(ntohs(code[i]), ascii[i], 15, &root);
/* Initialiseer de data */
sp = ascii + h->hCodeCount;
dp = (unsigned char *)MALLOC(h->hSourceLength);
if (dp)
*outData = dp;
else
return -1;
/* en start decoderen */
l = 0;
n = root;
for (i = 0; i < h->hCompressedLength && l < h->hSourceLength; i++)
{
for (j = 7; j >= 0; j--)
{
n = (sp[i] & (1 << j)) ? n->r : n->l;
if (!n)
{
FREE(dp);
*outData = NULL;
return -1;
}
if (n->t == nLeaf)
{
if (l < h->hSourceLength)
{
dp[l] = n->info;
if (++l == h->hSourceLength)
break;
n = root;
}
}
}
}
DeleteTrie(root);
return h->hSourceLength;
} /* DecodeHuffman */
