Function raxCompressNodeNoAlloc

rax.c:488–512

Turn the node 'n', that must be a node without any children, into a * compressed node representing a set of nodes linked one after the other * and having exactly one child each. The node can be a key or not: this * property and the associated value if any will be preserved. * * The function also returns a child node, since the last node of the * compressed chain cannot be part of the chain:

 * compressed chain cannot be part of the chain: it has zero children while
 * we can only compress inner nodes with exactly one child each. */
static inline raxNode *raxCompressNodeNoAlloc(raxNode *n, unsigned char *s,
                                              size_t len)
{
    assert(n->size == 0 && n->iscompr == 0);
    void *data = NULL; /* Initialized only to avoid warnings. */
    size_t newsize;

    debugf("Compress node: %.*s\n", (int)len,s);

    /* Make space in the parent node. */
    newsize = sizeof(raxNode)+len+raxPadding(len)+sizeof(raxNode*);
    if (n->iskey) {
        data = raxGetData(n); /* To restore it later. */
        if (!n->isnull) newsize += sizeof(void*);
    }
    raxNode *newn = rax_realloc(n,newsize);
    if (newn == NULL) return NULL;
    n = newn;

    n->iscompr = 1;
    n->size = len;
    memcpy(n->data,s,len);
    if (n->iskey) raxSetData(n,data);
    return n;
}

raxNode *raxCompressNode(raxNode *n, unsigned char *s, size_t len, raxNode **child) {
    /* Allocate the child to link to this node. */