tree-sitter/spec/runtime/helpers/spy_reader.cc

78 lines
1.9 KiB
C++

#include "runtime/helpers/spy_reader.h"
#include <string.h>
#include <algorithm>
#include "utf8proc.h"
using std::string;
static const char * spy_read(void *data, size_t *bytes_read) {
SpyReader *reader = static_cast<SpyReader *>(data);
string result = reader->content.substr(reader->position, reader->chunk_size);
reader->position += result.size();
reader->strings_read.back() += result;
*bytes_read = result.size();
memset(reader->buffer, 0, reader->chunk_size);
memcpy(reader->buffer, result.data(), result.size());
return reader->buffer;
}
static int spy_seek(void *data, TSLength position) {
SpyReader *reader = static_cast<SpyReader *>(data);
reader->strings_read.push_back("");
reader->position = position.bytes;
return 0;
}
SpyReader::SpyReader(string content, size_t chunk_size) :
buffer(new char[chunk_size]),
content(content),
position(0),
chunk_size(chunk_size) {}
void SpyReader::clear() {
strings_read.clear();
}
TSInput SpyReader::input() {
TSInput result;
result.data = this;
result.seek_fn = spy_seek;
result.read_fn = spy_read;
result.release_fn = nullptr;
return result;
}
long position_for_char_index(string str, size_t goal_index) {
size_t index = 0, position = 0;
int32_t dest_char;
while (index < goal_index) {
if (position >= str.size())
return -1;
position += utf8proc_iterate(
(uint8_t *)(str.data() + position),
str.size() - position,
&dest_char);
index++;
}
return position;
}
bool SpyReader::insert(size_t char_index, string text) {
long pos = position_for_char_index(content, char_index);
if (pos < 0) return false;
content.insert(pos, text);
return true;
}
bool SpyReader::erase(size_t char_index, size_t len) {
long pos = position_for_char_index(content, char_index);
if (pos < 0) return false;
content.erase(pos, len);
return true;
}
SpyReader::~SpyReader() {
delete buffer;
}