//Fill in doc from reading file.
static couchstore_error_t bp_to_doc(Doc **pDoc, Db *db, cs_off_t bp, couchstore_open_options options)
{
couchstore_error_t errcode = COUCHSTORE_SUCCESS;
int bodylen = 0;
char *docbody = NULL;
fatbuf *docbuf = NULL;
if (options & DECOMPRESS_DOC_BODIES) {
bodylen = pread_compressed(&db->file, bp, &docbody);
} else {
bodylen = pread_bin(&db->file, bp, &docbody);
}
error_unless(bodylen >= 0, bodylen); // if bodylen is negative it's an error code
error_unless(docbody || bodylen == 0, COUCHSTORE_ERROR_READ);
error_unless(docbuf = fatbuf_alloc(sizeof(Doc) + bodylen), COUCHSTORE_ERROR_ALLOC_FAIL);
*pDoc = (Doc *) fatbuf_get(docbuf, sizeof(Doc));
if (bodylen == 0) { //Empty doc
(*pDoc)->data.buf = NULL;
(*pDoc)->data.size = 0;
return 0;
}
(*pDoc)->data.buf = (char *) fatbuf_get(docbuf, bodylen);
(*pDoc)->data.size = bodylen;
memcpy((*pDoc)->data.buf, docbody, bodylen);
cleanup:
free(docbody);
if (errcode < 0) {
fatbuf_free(docbuf);
}
return errcode;
}
int modify_node(couchfile_modify_request *rq, couchfile_pointer_info *nptr,
int start, int end, couchfile_modify_result *dst)
{
eterm_buf current_node;
int curnode_pos = 0;
int read_size = 0;
int list_start_pos = 0;
int node_len = 0;
int node_bound = 0;
int errcode = 0;
int kpos = 0;
char node_type[MAXATOMLEN + 1];
node_type[0] = 0;
DBG("Enter modify_node. %d - %d\r\n", start, end);
if(start == end)
{
return 0;
}
if(nptr == NULL)
{
current_node = empty_root;
}
else
{
if((read_size = pread_bin(rq->fd, nptr->pointer, ¤t_node.buf)) < 0)
{
return ERROR_READ_FILE;
}
current_node.size = read_size;
DBG("... read node from %d\r\n", nptr->pointer);
curnode_pos++; //Skip over 131.
}
couchfile_modify_result *local_result = make_modres(rq);
ei_decode_tuple_header(current_node.buf, &curnode_pos, NULL);
if(ei_decode_atom(current_node.buf, &curnode_pos, node_type) < 0)
{
errcode = ERROR_PARSE;
goto cleanup;
}
list_start_pos = curnode_pos;
if(ei_decode_list_header(current_node.buf, &curnode_pos, &node_len) < 0)
{
errcode = ERROR_PARSE;
goto cleanup;
}
if(strcmp("kv_node", node_type) == 0)
{
local_result->node_type = KV_NODE;
while(start < end)
{
DBG("act on kvnode item\r\n");
if(node_bound >= node_len)
{ //We're at the end of a leaf node.
DBG(" ... exec action at end!\r\n");
switch(rq->actions[start].type)
{
case ACTION_INSERT:
local_result->modified = 1;
mr_push_action(&rq->actions[start], local_result);
break;
case ACTION_REMOVE:
local_result->modified = 1;
break;
case ACTION_FETCH:
if(rq->fetch_callback)
{
//not found
(*rq->fetch_callback)(rq, rq->actions[start].key, NULL);
}
break;
}
start++;
}
else
{
kpos = find_first_gteq(current_node.buf, list_start_pos,
rq->actions[start].cmp_key,
&rq->cmp, node_bound);
if(kpos < 0)
{
errcode = ERROR_PARSE;
goto cleanup;
}
//Add items from node_bound up to but not including the current
mr_push_kv_range(current_node.buf, list_start_pos, node_bound,
rq->cmp.list_pos, local_result);
if(rq->cmp.last_cmp_val > 0) // Node key > action key
{
DBG(" Inserting action before\r\n");
switch(rq->actions[start].type)
{
case ACTION_INSERT:
local_result->modified = 1;
mr_push_action(&rq->actions[start], local_result);
break;
case ACTION_REMOVE:
local_result->modified = 1;
break;
case ACTION_FETCH:
if(rq->fetch_callback)
{
//not found
(*rq->fetch_callback)(rq, rq->actions[start].key, NULL);
}
break;
}
start++;
node_bound = rq->cmp.list_pos;
}
else if(rq->cmp.last_cmp_val < 0) // Node key < action key
{
DBG(" -- Continue with this action\r\n");
node_bound = rq->cmp.list_pos + 1;
mr_push_kv_range(current_node.buf, list_start_pos, node_bound - 1,
node_bound, local_result);
}
else //Node key == action key
{
DBG(" Replacing value with action\r\n");
switch(rq->actions[start].type)
{
case ACTION_INSERT:
local_result->modified = 1;
mr_push_action(&rq->actions[start], local_result);
node_bound = rq->cmp.list_pos + 1;
break;
case ACTION_REMOVE:
local_result->modified = 1;
node_bound = rq->cmp.list_pos + 1;
break;
case ACTION_FETCH:
if(rq->fetch_callback)
{
eterm_buf cb_tmp;
int cb_vpos = kpos;
ei_decode_tuple_header(current_node.buf, &cb_vpos, NULL);
ei_skip_term(current_node.buf, &cb_vpos);
cb_tmp.buf = current_node.buf + cb_vpos;
cb_tmp.size = cb_vpos;
ei_skip_term(current_node.buf, &cb_vpos);
cb_tmp.size = cb_vpos - cb_tmp.size;
(*rq->fetch_callback)(rq, rq->actions[start].key, &cb_tmp);
}
node_bound = rq->cmp.list_pos;
break;
}
start++;
}
}
}
//Push any items past the end of what we dealt with onto result.
if(node_bound < node_len)
{
mr_push_kv_range(current_node.buf, list_start_pos, node_bound,
node_len, local_result);
}
}
else if(strcmp("kp_node", node_type) == 0)
{
local_result->node_type = KP_NODE;
while(start < end)
{
kpos = find_first_gteq(current_node.buf, list_start_pos,
rq->actions[start].cmp_key,
&rq->cmp, node_bound);
if(kpos < 0)
{
errcode = ERROR_PARSE;
goto cleanup;
}
if(rq->cmp.list_pos == (node_len - 1)) //got last item in kp_node
{
//Push all items in node onto mr
mr_push_kp_range(current_node.buf, list_start_pos, node_bound,
rq->cmp.list_pos, local_result);
DBG(" ...descending into final item of kpnode\r\n");
couchfile_pointer_info *desc = read_pointer(current_node.buf, kpos);
errcode = modify_node(rq, desc, start, end, local_result);
if(local_result->values_end->value.pointer != desc)
{
free(desc);
}
if(errcode < 0)
{
goto cleanup;
}
node_bound = node_len;
break;
}
else
{
//Get all actions with key <= the key of the current item in the
//kp_node
//Push items in node up to but not including current onto mr
mr_push_kp_range(current_node.buf, list_start_pos, node_bound,
rq->cmp.list_pos - 1, local_result);
int range_end = start;
while(range_end < end &&
((*rq->cmp.compare)(rq->actions[range_end].cmp_key, rq->cmp.last_cmp_key) <= 0))
{
range_end++;
}
DBG(" ...descending into item %d of kpnode\r\n", rq->cmp.list_pos);
node_bound = rq->cmp.list_pos + 1;
couchfile_pointer_info *desc = read_pointer(current_node.buf, kpos);
errcode = modify_node(rq, desc, start, range_end, local_result);
if(local_result->values_end->value.pointer != desc)
{
free(desc);
}
if(errcode < 0)
{
goto cleanup;
}
start = range_end;
}
}
DBG(".. Finished kp node, up to %d\r\n", node_bound);
if(node_bound < node_len)
{
//Processed all the actions but haven't exhausted this kpnode.
//push the rest of it onto the mr.
mr_push_kp_range(current_node.buf, list_start_pos, node_bound, node_len,
local_result);
}
}
else
{
errcode = ERROR_PARSE;
goto cleanup;
}
//If we've done modifications, write out the last leaf node.
errcode = flush_mr(local_result);
if(errcode == 0)
{
if(!local_result->modified && nptr != NULL)
{
//If we didn't do anything, give back the pointer to the original
mr_push_pointerinfo(nptr, dst);
}
else
{
//Otherwise, give back the pointers to the nodes we've created.
dst->modified = 1;
errcode = mr_move_pointers(local_result, dst);
}
}
cleanup:
free_modres(local_result);
if(current_node.buf != empty_root.buf)
{
free(current_node.buf);
}
return errcode;
}
