--- /dev/null
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/json/json.h"
+#include "src/core/lib/json/json_reader.h"
+#include "src/core/lib/json/json_writer.h"
+
+/* The json reader will construct a bunch of grpc_json objects and
+ * link them all up together in a tree-like structure that will represent
+ * the json data in memory.
+ *
+ * It also uses its own input as a scratchpad to store all of the decoded,
+ * unescaped strings. So we need to keep track of all these pointers in
+ * that opaque structure the reader will carry for us.
+ *
+ * Note that this works because the act of parsing json always reduces its
+ * input size, and never expands it.
+ */
+typedef struct {
+ grpc_json* top;
+ grpc_json* current_container;
+ grpc_json* current_value;
+ uint8_t* input;
+ uint8_t* key;
+ uint8_t* string;
+ uint8_t* string_ptr;
+ size_t remaining_input;
+} json_reader_userdata;
+
+/* This json writer will put everything in a big string.
+ * The point is that we allocate that string in chunks of 256 bytes.
+ */
+typedef struct {
+ char* output;
+ size_t free_space;
+ size_t string_len;
+ size_t allocated;
+} json_writer_userdata;
+
+/* This function checks if there's enough space left in the output buffer,
+ * and will enlarge it if necessary. We're only allocating chunks of 256
+ * bytes at a time (or multiples thereof).
+ */
+static void json_writer_output_check(void* userdata, size_t needed) {
+ json_writer_userdata* state = static_cast<json_writer_userdata*>(userdata);
+ if (state->free_space >= needed) return;
+ needed -= state->free_space;
+ /* Round up by 256 bytes. */
+ needed = (needed + 0xff) & ~0xffU;
+ state->output =
+ static_cast<char*>(gpr_realloc(state->output, state->allocated + needed));
+ state->free_space += needed;
+ state->allocated += needed;
+}
+
+/* These are needed by the writer's implementation. */
+static void json_writer_output_char(void* userdata, char c) {
+ json_writer_userdata* state = static_cast<json_writer_userdata*>(userdata);
+ json_writer_output_check(userdata, 1);
+ state->output[state->string_len++] = c;
+ state->free_space--;
+}
+
+static void json_writer_output_string_with_len(void* userdata, const char* str,
+ size_t len) {
+ json_writer_userdata* state = static_cast<json_writer_userdata*>(userdata);
+ json_writer_output_check(userdata, len);
+ memcpy(state->output + state->string_len, str, len);
+ state->string_len += len;
+ state->free_space -= len;
+}
+
+static void json_writer_output_string(void* userdata, const char* str) {
+ size_t len = strlen(str);
+ json_writer_output_string_with_len(userdata, str, len);
+}
+
+/* The reader asks us to clear our scratchpad. In our case, we'll simply mark
+ * the end of the current string, and advance our output pointer.
+ */
+static void json_reader_string_clear(void* userdata) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ if (state->string) {
+ GPR_ASSERT(state->string_ptr < state->input);
+ *state->string_ptr++ = 0;
+ }
+ state->string = state->string_ptr;
+}
+
+static void json_reader_string_add_char(void* userdata, uint32_t c) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ GPR_ASSERT(state->string_ptr < state->input);
+ GPR_ASSERT(c <= 0xff);
+ *state->string_ptr++ = static_cast<uint8_t>(c);
+}
+
+/* We are converting a UTF-32 character into UTF-8 here,
+ * as described by RFC3629.
+ */
+static void json_reader_string_add_utf32(void* userdata, uint32_t c) {
+ if (c <= 0x7f) {
+ json_reader_string_add_char(userdata, c);
+ } else if (c <= 0x7ff) {
+ uint32_t b1 = 0xc0 | ((c >> 6) & 0x1f);
+ uint32_t b2 = 0x80 | (c & 0x3f);
+ json_reader_string_add_char(userdata, b1);
+ json_reader_string_add_char(userdata, b2);
+ } else if (c <= 0xffff) {
+ uint32_t b1 = 0xe0 | ((c >> 12) & 0x0f);
+ uint32_t b2 = 0x80 | ((c >> 6) & 0x3f);
+ uint32_t b3 = 0x80 | (c & 0x3f);
+ json_reader_string_add_char(userdata, b1);
+ json_reader_string_add_char(userdata, b2);
+ json_reader_string_add_char(userdata, b3);
+ } else if (c <= 0x1fffff) {
+ uint32_t b1 = 0xf0 | ((c >> 18) & 0x07);
+ uint32_t b2 = 0x80 | ((c >> 12) & 0x3f);
+ uint32_t b3 = 0x80 | ((c >> 6) & 0x3f);
+ uint32_t b4 = 0x80 | (c & 0x3f);
+ json_reader_string_add_char(userdata, b1);
+ json_reader_string_add_char(userdata, b2);
+ json_reader_string_add_char(userdata, b3);
+ json_reader_string_add_char(userdata, b4);
+ }
+}
+
+/* We consider that the input may be a zero-terminated string. So we
+ * can end up hitting eof before the end of the alleged string length.
+ */
+static uint32_t json_reader_read_char(void* userdata) {
+ uint32_t r;
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+
+ if (state->remaining_input == 0) return GRPC_JSON_READ_CHAR_EOF;
+
+ r = *state->input++;
+ state->remaining_input--;
+
+ if (r == 0) {
+ state->remaining_input = 0;
+ return GRPC_JSON_READ_CHAR_EOF;
+ }
+
+ return r;
+}
+
+/* Helper function to create a new grpc_json object and link it into
+ * our tree-in-progress inside our opaque structure.
+ */
+static grpc_json* json_create_and_link(void* userdata, grpc_json_type type) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ grpc_json* json = grpc_json_create(type);
+
+ json->parent = state->current_container;
+ json->prev = state->current_value;
+ state->current_value = json;
+
+ if (json->prev) {
+ json->prev->next = json;
+ }
+ if (json->parent) {
+ if (!json->parent->child) {
+ json->parent->child = json;
+ }
+ if (json->parent->type == GRPC_JSON_OBJECT) {
+ json->key = reinterpret_cast<char*>(state->key);
+ }
+ }
+ if (!state->top) {
+ state->top = json;
+ }
+
+ return json;
+}
+
+static void json_reader_container_begins(void* userdata, grpc_json_type type) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ grpc_json* container;
+
+ GPR_ASSERT(type == GRPC_JSON_ARRAY || type == GRPC_JSON_OBJECT);
+
+ container = json_create_and_link(userdata, type);
+ state->current_container = container;
+ state->current_value = nullptr;
+}
+
+/* It's important to remember that the reader is mostly stateless, so it
+ * isn't trying to remember what the container was prior the one that just
+ * ends. Since we're keeping track of these for our own purpose, we are
+ * able to return that information back, which is useful for it to validate
+ * the input json stream.
+ *
+ * Also note that if we're at the top of the tree, and the last container
+ * ends, we have to return GRPC_JSON_TOP_LEVEL.
+ */
+static grpc_json_type json_reader_container_ends(void* userdata) {
+ grpc_json_type container_type = GRPC_JSON_TOP_LEVEL;
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+
+ GPR_ASSERT(state->current_container);
+
+ state->current_value = state->current_container;
+ state->current_container = state->current_container->parent;
+
+ if (state->current_container) {
+ container_type = state->current_container->type;
+ }
+
+ return container_type;
+}
+
+/* The next 3 functions basically are the reader asking us to use our string
+ * scratchpad for one of these 3 purposes.
+ *
+ * Note that in the set_number case, we're not going to try interpreting it.
+ * We'll keep it as a string, and leave it to the caller to evaluate it.
+ */
+static void json_reader_set_key(void* userdata) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ state->key = state->string;
+}
+
+static void json_reader_set_string(void* userdata) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ grpc_json* json = json_create_and_link(userdata, GRPC_JSON_STRING);
+ json->value = reinterpret_cast<char*>(state->string);
+}
+
+static int json_reader_set_number(void* userdata) {
+ json_reader_userdata* state = static_cast<json_reader_userdata*>(userdata);
+ grpc_json* json = json_create_and_link(userdata, GRPC_JSON_NUMBER);
+ json->value = reinterpret_cast<char*>(state->string);
+ return 1;
+}
+
+/* The object types true, false and null are self-sufficient, and don't need
+ * any more information beside their type.
+ */
+static void json_reader_set_true(void* userdata) {
+ json_create_and_link(userdata, GRPC_JSON_TRUE);
+}
+
+static void json_reader_set_false(void* userdata) {
+ json_create_and_link(userdata, GRPC_JSON_FALSE);
+}
+
+static void json_reader_set_null(void* userdata) {
+ json_create_and_link(userdata, GRPC_JSON_NULL);
+}
+
+static grpc_json_reader_vtable reader_vtable = {
+ json_reader_string_clear, json_reader_string_add_char,
+ json_reader_string_add_utf32, json_reader_read_char,
+ json_reader_container_begins, json_reader_container_ends,
+ json_reader_set_key, json_reader_set_string,
+ json_reader_set_number, json_reader_set_true,
+ json_reader_set_false, json_reader_set_null};
+
+/* And finally, let's define our public API. */
+grpc_json* grpc_json_parse_string_with_len(char* input, size_t size) {
+ grpc_json_reader reader;
+ json_reader_userdata state;
+ grpc_json* json = nullptr;
+ grpc_json_reader_status status;
+
+ if (!input) return nullptr;
+
+ state.top = state.current_container = state.current_value = nullptr;
+ state.string = state.key = nullptr;
+ state.string_ptr = state.input = reinterpret_cast<uint8_t*>(input);
+ state.remaining_input = size;
+ grpc_json_reader_init(&reader, &reader_vtable, &state);
+
+ status = grpc_json_reader_run(&reader);
+ json = state.top;
+
+ if ((status != GRPC_JSON_DONE) && json) {
+ grpc_json_destroy(json);
+ json = nullptr;
+ }
+
+ return json;
+}
+
+#define UNBOUND_JSON_STRING_LENGTH 0x7fffffff
+
+grpc_json* grpc_json_parse_string(char* input) {
+ return grpc_json_parse_string_with_len(input, UNBOUND_JSON_STRING_LENGTH);
+}
+
+static void json_dump_recursive(grpc_json_writer* writer, grpc_json* json,
+ int in_object) {
+ while (json) {
+ if (in_object) grpc_json_writer_object_key(writer, json->key);
+
+ switch (json->type) {
+ case GRPC_JSON_OBJECT:
+ case GRPC_JSON_ARRAY:
+ grpc_json_writer_container_begins(writer, json->type);
+ if (json->child)
+ json_dump_recursive(writer, json->child,
+ json->type == GRPC_JSON_OBJECT);
+ grpc_json_writer_container_ends(writer, json->type);
+ break;
+ case GRPC_JSON_STRING:
+ grpc_json_writer_value_string(writer, json->value);
+ break;
+ case GRPC_JSON_NUMBER:
+ grpc_json_writer_value_raw(writer, json->value);
+ break;
+ case GRPC_JSON_TRUE:
+ grpc_json_writer_value_raw_with_len(writer, "true", 4);
+ break;
+ case GRPC_JSON_FALSE:
+ grpc_json_writer_value_raw_with_len(writer, "false", 5);
+ break;
+ case GRPC_JSON_NULL:
+ grpc_json_writer_value_raw_with_len(writer, "null", 4);
+ break;
+ default:
+ GPR_UNREACHABLE_CODE(abort());
+ }
+ json = json->next;
+ }
+}
+
+static grpc_json_writer_vtable writer_vtable = {
+ json_writer_output_char, json_writer_output_string,
+ json_writer_output_string_with_len};
+
+char* grpc_json_dump_to_string(grpc_json* json, int indent) {
+ grpc_json_writer writer;
+ json_writer_userdata state;
+
+ state.output = nullptr;
+ state.free_space = state.string_len = state.allocated = 0;
+ grpc_json_writer_init(&writer, indent, &writer_vtable, &state);
+
+ json_dump_recursive(&writer, json, 0);
+
+ json_writer_output_char(&state, 0);
+
+ return state.output;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff