// Insert the given utf8 string into the rope at the specified position.
static ROPE_RESULT rope_insert_at_iter(rope *r, rope_node *e, rope_iter *iter, const uint8_t *str) {
// iter.offset contains how far (in characters) into the current element to skip.
// Figure out how much that is in bytes.
size_t offset_bytes = 0;
// The insertion offset into the destination node.
size_t offset = iter->s[0].skip_size;
if (offset) {
assert(offset <= e->nexts[0].skip_size);
offset_bytes = count_bytes_in_utf8(e->str, offset);
}
// We might be able to insert the new data into the current node, depending on
// how big it is. We'll count the bytes, and also check that its valid utf8.
ssize_t num_inserted_bytes = bytelen_and_check_utf8(str);
if (num_inserted_bytes == -1) return ROPE_INVALID_UTF8;
// Can we insert into the current node?
bool insert_here = e->num_bytes + num_inserted_bytes <= ROPE_NODE_STR_SIZE;
// Can we insert into the subsequent node?
rope_node *next = NULL;
if (!insert_here && offset_bytes == e->num_bytes) {
next = e->nexts[0].node;
// We can insert into the subsequent node if:
// - We can't insert into the current node
// - There _is_ a next node to insert into
// - The insert would be at the start of the next node
// - There's room in the next node
if (next && next->num_bytes + num_inserted_bytes <= ROPE_NODE_STR_SIZE) {
offset = offset_bytes = 0;
for (int i = 0; i < next->height; i++) {
iter->s[i].node = next;
// tree offset nodes will not be used.
}
e = next;
insert_here = true;
}
}
if (insert_here) {
// First move the current bytes later on in the string.
if (offset_bytes < e->num_bytes) {
memmove(&e->str[offset_bytes + num_inserted_bytes],
&e->str[offset_bytes],
e->num_bytes - offset_bytes);
}
// Then copy in the string bytes
memcpy(&e->str[offset_bytes], str, num_inserted_bytes);
e->num_bytes += num_inserted_bytes;
r->num_bytes += num_inserted_bytes;
size_t num_inserted_chars = strlen_utf8(str);
r->num_chars += num_inserted_chars;
// .... aaaand update all the offset amounts.
#if ROPE_WCHAR
size_t num_inserted_wchars = count_wchars_in_utf8(str, num_inserted_chars);
update_offset_list(r, iter, num_inserted_chars, num_inserted_wchars);
#else
update_offset_list(r, iter, num_inserted_chars);
#endif
} else {
// There isn't room. We'll need to add at least one new node to the rope.
// If we're not at the end of the current node, we'll need to remove
// the end of the current node's data and reinsert it later.
size_t num_end_chars, num_end_bytes = e->num_bytes - offset_bytes;
if (num_end_bytes) {
// We'll pretend like the character have been deleted from the node, while leaving
// the bytes themselves there (for later).
e->num_bytes = offset_bytes;
num_end_chars = e->nexts[0].skip_size - offset;
#if ROPE_WCHAR
size_t num_end_wchars = count_wchars_in_utf8(&e->str[offset_bytes], num_end_chars);
update_offset_list(r, iter, -num_end_chars, -num_end_wchars);
#else
update_offset_list(r, iter, -num_end_chars);
#endif
r->num_chars -= num_end_chars;
r->num_bytes -= num_end_bytes;
}
// Now we insert new nodes containing the new character data. The data must be broken into
// pieces of with a maximum size of ROPE_NODE_STR_SIZE. Node boundaries must not occur in the
// middle of a utf8 codepoint.
size_t str_offset = 0;
while (str_offset < num_inserted_bytes) {
size_t new_node_bytes = 0;
size_t new_node_chars = 0;
while (str_offset + new_node_bytes < num_inserted_bytes) {
size_t cs = codepoint_size(str[str_offset + new_node_bytes]);
if (cs + new_node_bytes > ROPE_NODE_STR_SIZE) {
break;
} else {
new_node_bytes += cs;
new_node_chars++;
}
}
insert_at(r, iter, &str[str_offset], new_node_bytes, new_node_chars);
str_offset += new_node_bytes;
}
if (num_end_bytes) {
insert_at(r, iter, &e->str[offset_bytes], num_end_bytes, num_end_chars);
}
}
return ROPE_OK;
}
// Insert the given utf8 string into the rope at the specified position.
void rope_insert(rope *r, size_t pos, const uint8_t *str) {
assert(r);
assert(str);
#ifdef DEBUG
_rope_check(r);
#endif
pos = MIN(pos, r->num_chars);
// There's a good chance we'll have to rewrite a bunch of next pointers and a bunch
// of offsets. This variable will store pointers to the elements which need to
// be changed.
rope_node *nodes[UINT8_MAX];
size_t tree_offsets[UINT8_MAX];
// This is the number of characters to skip in the current node.
size_t offset;
// First we need to search for the node where we'll insert the string.
rope_node *e = go_to_node(r, pos, &offset, nodes, tree_offsets);
// offset contains how far (in characters) into the current element to skip.
// Figure out how much that is in bytes.
size_t offset_bytes = 0;
if (e && offset) {
assert(offset <= e->num_bytes);
offset_bytes = count_bytes_in_chars(e->str, offset);
}
// Maybe we can insert the characters into the current node?
size_t num_inserted_bytes = strlen((char *)str);
// Can we insert into the current node?
bool insert_here = e && e->num_bytes + num_inserted_bytes <= ROPE_NODE_STR_SIZE;
// Can we insert into the subsequent node?
bool insert_next = false;
rope_node *next = NULL;
if (!insert_here) {
next = e ? e->nexts[0].node : (r->num_chars ? r->heads[0].node : NULL);
// We can insert into the subsequent node if:
// - We can't insert into the current node
// - There _is_ a next node to insert into
// - The insert would be at the start of the next node
// - There's room in the next node
insert_next = next
&& (e == NULL || offset_bytes == e->num_bytes)
&& next->num_bytes + num_inserted_bytes <= ROPE_NODE_STR_SIZE;
}
if (insert_here || insert_next) {
if (insert_next) {
offset = offset_bytes = 0;
for (int i = 0; i < next->height; i++) {
nodes[i] = next;
// tree offset nodes not used.
}
e = next;
}
// First move the current bytes later on in the string.
if (offset_bytes < e->num_bytes) {
memmove(&e->str[offset_bytes + num_inserted_bytes],
&e->str[offset_bytes],
e->num_bytes - offset_bytes);
}
// Then copy in the string bytes
memcpy(&e->str[offset_bytes], str, num_inserted_bytes);
e->num_bytes += num_inserted_bytes;
r->num_bytes += num_inserted_bytes;
size_t num_inserted_chars = strlen_utf8(str);
r->num_chars += num_inserted_chars;
// .... aaaand update all the offset amounts.
update_offset_list(r, nodes, num_inserted_chars);
} else {
// There isn't room. We'll need to add at least one new node to the rope.
// If we're not at the end of the current node, we'll need to remove
// the end of the current node's data and reinsert it later.
size_t num_end_bytes = 0, num_end_chars;
if (e) {
num_end_bytes = e->num_bytes - offset_bytes;
e->num_bytes = offset_bytes;
if (num_end_bytes) {
// Count out characters.
num_end_chars = e->nexts[0].skip_size - offset;
update_offset_list(r, nodes, -num_end_chars);
r->num_chars -= num_end_chars;
r->num_bytes -= num_end_bytes;
}
}
// Now, we insert new node[s] containing the data. The data must
// be broken into pieces of with a maximum size of ROPE_NODE_STR_SIZE.
// Node boundaries do not occur in the middle of a utf8 codepoint.
size_t str_offset = 0;
while (str_offset < num_inserted_bytes) {
size_t new_node_bytes = 0;
size_t new_node_chars = 0;
while (str_offset + new_node_bytes < num_inserted_bytes) {
size_t cs = codepoint_size(str[str_offset + new_node_bytes]);
if (cs + new_node_bytes > ROPE_NODE_STR_SIZE) {
break;
} else {
new_node_bytes += cs;
new_node_chars++;
}
}
insert_at(r, pos, &str[str_offset], new_node_bytes, new_node_chars, nodes, tree_offsets);
pos += new_node_chars;
str_offset += new_node_bytes;
}
if (num_end_bytes) {
insert_at(r, pos, &e->str[offset_bytes], num_end_bytes, num_end_chars, nodes, tree_offsets);
}
}
#ifdef DEBUG
_rope_check(r);
#endif
}