jasder
/
simdjson
1
0
Fork 0
Code Issues Pull Requests Releases 2 Wiki Activity

Remove backslash unescaping from JSON pointer impl 

Also speed up non-escaped key lookup
This commit is contained in:
John Keiser 2020-03-24 17:13:43 -07:00
parent 65f999b7b7
commit b28cafc1d1
4 changed files with 47 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/simdjson/document.h
View File

@ -1110,6 +1110,7 @@ private:
/** The result of a JSON navigation that may fail. */
class document::element_result : public simdjson_result<document::element> {
public:
really_inline element_result() noexcept;
really_inline element_result(element value) noexcept;
really_inline element_result(error_code error) noexcept;
@ -1146,6 +1147,7 @@ public:
/** The result of a JSON conversion that may fail. */
class document::array_result : public simdjson_result<document::array> {
public:
really_inline array_result() noexcept;
really_inline array_result(array value) noexcept;
really_inline array_result(error_code error) noexcept;
@ -1163,6 +1165,7 @@ public:
/** The result of a JSON conversion that may fail. */
class document::object_result : public simdjson_result<document::object> {
public:
really_inline object_result() noexcept;
really_inline object_result(object value) noexcept;
really_inline object_result(error_code error) noexcept;

10
include/simdjson/error.h
View File

@ -118,6 +118,11 @@ struct simdjson_result : public std::pair<T, error_code> {
#endif // SIMDJSON_EXCEPTIONS
/**
* Create a new empty result with error = UNINITIALIZED.
*/
simdjson_result() noexcept : simdjson_result(UNINITIALIZED) {}
/**
* Create a new error result.
*/
@ -180,6 +185,11 @@ struct simdjson_move_result : std::pair<T, error_code> {
#endif
/**
* Create a new empty result with error = UNINITIALIZED.
*/
simdjson_move_result() noexcept : simdjson_move_result(UNINITIALIZED) {}
/**
* Create a new error result.
*/

74
include/simdjson/inline/document.h
View File

@ -16,6 +16,7 @@ namespace simdjson {
//
// element_result inline implementation
//
really_inline document::element_result::element_result() noexcept : simdjson_result<element>() {}
really_inline document::element_result::element_result(element value) noexcept : simdjson_result<element>(value) {}
really_inline document::element_result::element_result(error_code error) noexcept : simdjson_result<element>(error) {}
inline simdjson_result<bool> document::element_result::is_null() const noexcept {
@ -111,6 +112,7 @@ inline document::element_result::operator document::object() const noexcept(fals
//
// array_result inline implementation
//
really_inline document::array_result::array_result() noexcept : simdjson_result<array>() {}
really_inline document::array_result::array_result(array value) noexcept : simdjson_result<array>(value) {}
really_inline document::array_result::array_result(error_code error) noexcept : simdjson_result<array>(error) {}
@ -146,6 +148,7 @@ inline document::element_result document::array_result::at(size_t index) const n
//
// object_result inline implementation
//
really_inline document::object_result::object_result() noexcept : simdjson_result<object>() {}
really_inline document::object_result::object_result(object value) noexcept : simdjson_result<object>(value) {}
really_inline document::object_result::object_result(error_code error) noexcept : simdjson_result<object>(error) {}
@ -805,53 +808,38 @@ inline document::element_result document::object::operator[](const char *json_po
return (*this)[std::string_view(json_pointer)];
}
inline document::element_result document::object::at(std::string_view json_pointer) const noexcept {
// Unescape the key
std::string unescaped;
unescaped.reserve(json_pointer.length());
size_t i;
for (i = 0; i < json_pointer.length() && json_pointer[i] != '/'; i++) {
switch (json_pointer[i]) {
// Handle ~ escaping: ~0 = ~, ~1 = /
case '~': {
i++;
// ~ at end of string is invalid
if (i >= json_pointer.length()) { RETURN_ERROR(INVALID_JSON_POINTER, "~ at end of string in JSON pointer"); }
switch (json_pointer[i]) {
case '0':
unescaped.push_back('~');
break;
case '1':
unescaped.push_back('/');
break;
default:
RETURN_ERROR(INVALID_JSON_POINTER, "Unexpected ~ escape character in JSON pointer");
}
break;
}
// TODO backslash doesn't appear to be a thing in JSON pointer
case '\\': {
i++;
// backslash at end of string is invalid
if (i >= json_pointer.length()) { RETURN_ERROR(INVALID_JSON_POINTER, "~ at end of string in JSON pointer"); }
// Check for invalid escape characters
if (json_pointer[i] != '\\' && json_pointer[i] != '"' && json_pointer[i] > 0x1F) {
RETURN_ERROR(INVALID_JSON_POINTER, "Invalid backslash escape in JSON pointer");
}
unescaped.push_back(json_pointer[i]);
break;
}
default:
unescaped.push_back(json_pointer[i]);
break;
}
}
size_t slash = json_pointer.find('/');
std::string_view key = json_pointer.substr(0, slash);
// Grab the child with the given key
auto child = at_key(unescaped);
document::element_result child;
// If there is an escape character in the key, unescape it and then get the child.
size_t escape = key.find('~');
if (escape != std::string_view::npos) {
// Unescape the key
std::string unescaped(key);
do {
switch (unescaped[escape+1]) {
case '0':
unescaped.replace(escape, 2, "~");
break;
case '1':
unescaped.replace(escape, 2, "/");
break;
default:
RETURN_ERROR(INVALID_JSON_POINTER, "Unexpected ~ escape character in JSON pointer");
}
escape = unescaped.find('~', escape+1);
} while (escape != std::string::npos);
child = at_key(unescaped);
} else {
child = at_key(key);
}
// If there is a /, we have to recurse and look up more of the path
if (i < json_pointer.length()) {
child = child.at(json_pointer.substr(i+1));
if (slash != std::string_view::npos) {
child = child.at(json_pointer.substr(slash+1));
}
return child;

6
tests/pointercheck.cpp
View File

@ -60,9 +60,9 @@ bool json_pointer_failure_test(const char *json_pointer, error_code expected_fai
int main() {
if (
json_pointer_success_test(R"(/~1~001abc/1/\\\" 0/0)", "value0") &&
json_pointer_success_test(R"(/~1~001abc/1/\\\" 0/1)", "value1") &&
json_pointer_failure_test(R"(/~1~001abc/1/\\\" 0/2)", INDEX_OUT_OF_BOUNDS) && // index actually out of bounds
json_pointer_success_test("/~1~001abc/1/\\\" 0/0", "value0") &&
json_pointer_success_test("/~1~001abc/1/\\\" 0/1", "value1") &&
json_pointer_failure_test("/~1~001abc/1/\\\" 0/2", INDEX_OUT_OF_BOUNDS) && // index actually out of bounds
json_pointer_success_test("/arr") && // get array
json_pointer_failure_test("/arr/0", INDEX_OUT_OF_BOUNDS) && // array index 0 out of bounds on empty array
json_pointer_success_test("/~1~001abc") && // get object