fetch.c
No OneTemporary
Actions

Size

20 KB

Referenced Files

None

Subscribers

None

fetch.c
View Options

	#include <compat.h> // IWYU pragma: keep

	#include <stdbool.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <strings.h>
	#include <uv.h>
	#include <utarray.h>

	#include "ant.h"
	#include "common.h"
	#include "errors.h"
	#include "internal.h"
	#include "runtime.h"
	#include "esm/remote.h"
	#include "gc/modules.h"
	#include "modules/abort.h"
	#include "modules/assert.h"
	#include "modules/buffer.h"
	#include "modules/fetch.h"
	#include "modules/headers.h"
	#include "modules/http.h"
	#include "modules/request.h"
	#include "modules/response.h"
	#include "modules/url.h"
	#include "streams/readable.h"

	typedef struct fetch_request_s {
	ant_t *js;

	ant_value_t promise;
	ant_value_t request_obj;
	ant_value_t response_obj;
	ant_value_t abort_listener;
	ant_value_t upload_reader;
	ant_value_t upload_read_promise;
	ant_http_request_t *http_req;

	int refs;
	bool settled;
	bool aborted;
	bool response_started;
	} fetch_request_t;

	static UT_array *pending_requests = NULL;

	static void fetch_request_retain(fetch_request_t *req) {
	if (req) req->refs++;
	}

	static void remove_pending_request(fetch_request_t *req) {
	if (!req \|\| !pending_requests) return;

	fetch_request_t **p = NULL;
	unsigned int i = 0;

	while ((p = (fetch_request_t **)utarray_next(pending_requests, p))) {
	if (*p == req) { utarray_erase(pending_requests, i, 1); return; } i++;
	}
	}

	static void destroy_fetch_request(fetch_request_t *req) {
	if (!req) return;

	if (abort_signal_is_signal(request_get_signal(req->request_obj)) && is_callable(req->abort_listener))
	abort_signal_remove_listener(req->js, request_get_signal(req->request_obj), req->abort_listener);

	remove_pending_request(req);
	free(req);
	}

	static void fetch_request_release(fetch_request_t *req) {
	if (!req) return;
	if (--req->refs == 0) destroy_fetch_request(req);
	}

	static ant_value_t fetch_type_error(ant_t js, const char message) {
	return js_mkerr_typed(js, JS_ERR_TYPE, "%s", message ? message : "fetch failed");
	}

	static ant_value_t fetch_rejection_reason(ant_t *js, ant_value_t value) {
	if (!is_err(value)) return value;
	if (js->thrown_exists) {
	ant_value_t reason = js->thrown_value;
	js->thrown_exists = false;
	js->thrown_value = js_mkundef();
	js->thrown_stack = js_mkundef();
	return reason;
	}
	return value;
	}

	static void fetch_cancel_request_body(fetch_request_t *req, ant_value_t reason) {
	request_data_t *data = request_get_data(req->request_obj);
	ant_value_t stream = js_get_slot(req->request_obj, SLOT_REQUEST_BODY_STREAM);

	if (!data \|\| !data->body_is_stream \|\| !rs_is_stream(stream)) return;
	readable_stream_cancel(req->js, stream, reason);
	}

	static void fetch_error_response_body(fetch_request_t *req, ant_value_t reason) {
	ant_value_t stream = js_get_slot(req->response_obj, SLOT_RESPONSE_BODY_STREAM);
	if (rs_is_stream(stream)) readable_stream_error(req->js, stream, reason);
	}

	static void fetch_reject(fetch_request_t *req, ant_value_t reason) {
	if (!req) return;

	if (!req->settled) {
	req->settled = true;
	js_reject_promise(req->js, req->promise, reason);
	}

	fetch_cancel_request_body(req, reason);
	if (is_object_type(req->response_obj)) fetch_error_response_body(req, reason);
	}

	static void fetch_resolve(fetch_request_t *req, ant_value_t response_obj) {
	if (!req \|\| req->settled) return;
	req->settled = true;
	req->response_started = true;
	req->response_obj = response_obj;
	js_resolve_promise(req->js, req->promise, response_obj);
	}

	static bool fetch_is_http_url(const char *url) {
	return strncmp(url, "http://", 7) == 0 \|\| strncmp(url, "https://", 8) == 0;
	}

	static char fetch_build_request_url(request_data_t request) {
	if (!request) return NULL;
	return build_href(&request->url);
	}

	typedef struct {
	ant_http_header_t *head;
	ant_http_header_t **tail;
	bool failed;
	bool has_user_agent;
	bool has_accept;
	bool has_accept_language;
	bool has_sec_fetch_mode;
	bool has_accept_encoding;
	} fetch_header_builder_t;

	static void fetch_collect_header(const char name, const char value, void *ctx) {
	fetch_header_builder_t builder = (fetch_header_builder_t )ctx;
	ant_http_header_t *header = NULL;

	if (!builder \|\| builder->failed) return;
	if (name && strcasecmp(name, "user-agent") == 0) builder->has_user_agent = true;
	if (name && strcasecmp(name, "accept") == 0) builder->has_accept = true;
	if (name && strcasecmp(name, "accept-language") == 0) builder->has_accept_language = true;
	if (name && strcasecmp(name, "sec-fetch-mode") == 0) builder->has_sec_fetch_mode = true;
	if (name && strcasecmp(name, "accept-encoding") == 0) builder->has_accept_encoding = true;
	header = calloc(1, sizeof(ant_http_header_t));
	if (!header) {
	builder->failed = true;
	return;
	}

	header->name = strdup(name ? name : "");
	header->value = strdup(value ? value : "");
	if (!header->name \|\| !header->value) {
	free(header->name);
	free(header->value);
	free(header);
	builder->failed = true;
	return;
	}

	*builder->tail = header;
	builder->tail = &header->next;
	}

	static bool fetch_append_header(fetch_header_builder_t builder, const char name, const char *value) {
	ant_http_header_t *header = NULL;

	if (!builder \|\| builder->failed) return false;
	header = calloc(1, sizeof(ant_http_header_t));
	if (!header) {
	builder->failed = true;
	return false;
	}

	header->name = strdup(name);
	header->value = strdup(value);
	if (!header->name \|\| !header->value) {
	free(header->name);
	free(header->value);
	free(header);
	builder->failed = true;
	return false;
	}

	*builder->tail = header;
	builder->tail = &header->next;
	return true;
	}

	static ant_http_header_t *fetch_build_http_headers(ant_value_t request_obj) {
	fetch_header_builder_t builder = {0};
	char user_agent[256] = {0};

	builder.tail = &builder.head;
	headers_for_each(request_get_headers(request_obj), fetch_collect_header, &builder);

	if (builder.failed) {
	ant_http_headers_free(builder.head);
	return NULL;
	}

	if (!builder.has_accept && !fetch_append_header(&builder, "accept", "/")) {
	ant_http_headers_free(builder.head);
	return NULL;
	}
	if (!builder.has_accept_language && !fetch_append_header(&builder, "accept-language", "*")) {
	ant_http_headers_free(builder.head);
	return NULL;
	}
	if (!builder.has_sec_fetch_mode && !fetch_append_header(&builder, "sec-fetch-mode", "cors")) {
	ant_http_headers_free(builder.head);
	return NULL;
	}
	if (!builder.has_accept_encoding && !fetch_append_header(&builder, "accept-encoding", "br, gzip, deflate")) {
	ant_http_headers_free(builder.head);
	return NULL;
	}
	if (builder.has_user_agent) return builder.head;

	snprintf(user_agent, sizeof(user_agent), "ant/%s", ANT_VERSION);
	if (!fetch_append_header(&builder, "user-agent", user_agent)) {
	ant_http_headers_free(builder.head);
	return NULL;
	}

	return builder.head;
	}

	static ant_value_t fetch_headers_from_http(ant_t js, const ant_http_header_t headers) {
	ant_value_t hdrs = headers_create_empty(js);
	if (is_err(hdrs)) return hdrs;

	for (const ant_http_header_t *entry = headers; entry; entry = entry->next) {
	ant_value_t step = headers_append_value(
	js, hdrs,
	js_mkstr(js, entry->name, strlen(entry->name)),
	js_mkstr(js, entry->value, strlen(entry->value))
	);
	if (is_err(step)) return step;
	}

	return hdrs;
	}

	static ant_value_t fetch_create_chunk(ant_t js, const uint8_t data, size_t len) {
	ArrayBufferData *ab = create_array_buffer_data(len);
	if (!ab) return js_mkerr(js, "out of memory");
	if (len > 0) memcpy(ab->data, data, len);
	return create_typed_array(js, TYPED_ARRAY_UINT8, ab, 0, len, "Uint8Array");
	}

	static bool fetch_get_upload_chunk(ant_value_t value, const uint8_t *out, size_t len) {
	ant_value_t slot = js_get_slot(value, SLOT_BUFFER);
	TypedArrayData ta = (TypedArrayData )js_gettypedarray(slot);

	if (!ta \|\| ta->type != TYPED_ARRAY_UINT8) return false;
	if (!ta->buffer \|\| ta->buffer->is_detached) {
	*out = NULL;
	*len = 0;
	return true;
	}

	*out = ta->buffer->data + ta->byte_offset;
	*len = ta->byte_length;
	return true;
	}

	static void fetch_http_on_response(ant_http_request_t http_req, const ant_http_response_t resp, void *user_data) {
	fetch_request_t req = (fetch_request_t )user_data;

	ant_t *js = req->js;
	ant_value_t headers = 0;
	ant_value_t stream = 0;
	ant_value_t response = 0;

	char *url = NULL;
	if (req->aborted) return;

	headers = fetch_headers_from_http(js, resp->headers);
	if (is_err(headers)) {
	fetch_reject(req, fetch_rejection_reason(js, headers));
	ant_http_request_cancel(http_req);
	return;
	}

	stream = rs_create_stream(js, js_mkundef(), js_mkundef(), 1.0);
	if (is_err(stream)) {
	fetch_reject(req, fetch_rejection_reason(js, stream));
	ant_http_request_cancel(http_req);
	return;
	}

	url = fetch_build_request_url(request_get_data(req->request_obj));
	response = response_create_fetched(
	js, resp->status, resp->status_text, url, headers, NULL, 0, stream, NULL
	);
	free(url);

	if (is_err(response)) {
	fetch_reject(req, fetch_rejection_reason(js, response));
	ant_http_request_cancel(http_req);
	return;
	}

	fetch_resolve(req, response);
	}

	static void fetch_http_on_body(ant_http_request_t http_req, const uint8_t chunk, size_t len, void *user_data) {
	fetch_request_t req = (fetch_request_t )user_data;
	ant_t *js = req->js;
	ant_value_t stream = 0;
	ant_value_t controller = 0;
	ant_value_t value = 0;
	ant_value_t step = 0;

	(void)http_req;
	if (req->aborted \|\| !is_object_type(req->response_obj)) return;

	stream = js_get_slot(req->response_obj, SLOT_RESPONSE_BODY_STREAM);
	if (!rs_is_stream(stream)) return;

	controller = rs_stream_controller(js, stream);
	value = fetch_create_chunk(js, chunk, len);
	if (is_err(value)) {
	fetch_error_response_body(req, fetch_rejection_reason(js, value));
	ant_http_request_cancel(http_req);
	return;
	}

	step = rs_controller_enqueue(js, controller, value);
	if (is_err(step)) {
	fetch_error_response_body(req, fetch_rejection_reason(js, step));
	ant_http_request_cancel(http_req);
	}
	}

	static ant_value_t fetch_transport_reason(fetch_request_t req, ant_http_result_t result, const char error_message) {
	if (result == ANT_HTTP_RESULT_ABORTED && req->aborted) {
	ant_value_t signal = request_get_signal(req->request_obj);
	return abort_signal_get_reason(signal);
	}

	return fetch_type_error(req->js, error_message ? error_message : "fetch failed");
	}

	static void fetch_http_on_complete(
	ant_http_request_t *http_req,
	ant_http_result_t result,
	int error_code, const char error_message, void user_data
	) {
	fetch_request_t req = (fetch_request_t )user_data;

	ant_t *js = req->js;
	ant_value_t stream = 0;
	ant_value_t controller = 0;
	ant_value_t reason = 0;
	req->http_req = NULL;

	if (result != ANT_HTTP_RESULT_OK \|\| error_code != 0) {
	reason = fetch_transport_reason(req, result, error_message);
	if (is_object_type(req->response_obj)) fetch_error_response_body(req, reason);
	else fetch_reject(req, reason);
	fetch_request_release(req);
	return;
	}

	if (is_object_type(req->response_obj)) {
	stream = js_get_slot(req->response_obj, SLOT_RESPONSE_BODY_STREAM);
	if (rs_is_stream(stream)) {
	controller = rs_stream_controller(js, stream);
	rs_controller_close(js, controller);
	}
	} else fetch_reject(req, fetch_type_error(js, "fetch completed without a response"));

	fetch_request_release(req);
	}

	static char fetch_data_url_content_type(const char url) {
	const char *header = url + 5;
	const char *comma = strchr(header, ',');
	const char *base64 = NULL;
	size_t len = 0;

	if (!comma) return strdup("text/plain;charset=US-ASCII");
	base64 = strstr(header, ";base64");
	len = base64 && base64 < comma ? (size_t)(base64 - header) : (size_t)(comma - header);
	if (len == 0) return strdup("text/plain;charset=US-ASCII");

	return strndup(header, len);
	}

	static bool fetch_handle_data_url(fetch_request_t *req) {
	ant_t *js = req->js;
	request_data_t *request = request_get_data(req->request_obj);

	char *url = fetch_build_request_url(request);
	size_t len = 0;
	char *body = NULL;
	char *content_type = NULL;

	ant_value_t headers = 0;
	ant_value_t response = 0;

	if (!url \|\| !esm_is_data_url(url)) {
	free(url);
	return false;
	}

	body = esm_parse_data_url(url, &len);
	content_type = fetch_data_url_content_type(url);
	headers = headers_create_empty(js);

	if (!body \|\| !content_type \|\| is_err(headers)) {
	free(url);
	free(body);
	free(content_type);
	fetch_reject(req, fetch_type_error(js, "Failed to decode data URL"));
	fetch_request_release(req);
	return true;
	}

	headers_set_literal(js, headers, "content-type", content_type);
	response = response_create_fetched(
	js, 200, "OK", url, headers, (const uint8_t *)body, len, js_mkundef(), content_type
	);

	free(url);
	free(body);
	free(content_type);

	if (is_err(response)) {
	fetch_reject(req, fetch_rejection_reason(js, response));
	} else fetch_resolve(req, response);

	fetch_request_release(req);
	return true;
	}

	static ant_value_t fetch_upload_on_reject(ant_t js, ant_value_t args, int nargs) {
	fetch_request_t req = (fetch_request_t )(uintptr_t)(size_t)js_getnum(js_get_slot(js->current_func, SLOT_DATA));
	ant_value_t reason = (nargs > 0) ? args[0] : js_mkundef();

	if (!req) return js_mkundef();
	req->upload_read_promise = js_mkundef();

	if (!req->aborted) {
	if (req->http_req) ant_http_request_cancel(req->http_req);
	fetch_reject(req, reason);
	if (!req->http_req) fetch_request_release(req);
	}

	fetch_request_release(req);
	return js_mkundef();
	}

	static void fetch_upload_schedule_next_read(fetch_request_t *req);
	static ant_value_t fetch_upload_on_read(ant_t js, ant_value_t args, int nargs) {
	fetch_request_t req = (fetch_request_t )(uintptr_t)(size_t)js_getnum(js_get_slot(js->current_func, SLOT_DATA));

	ant_value_t result = (nargs > 0) ? args[0] : js_mkundef();
	ant_value_t done = 0;
	ant_value_t value = 0;

	const uint8_t *chunk = NULL;
	size_t chunk_len = 0;
	int rc = 0;

	if (!req) return js_mkundef();
	req->upload_read_promise = js_mkundef();

	if (req->aborted \|\| !req->http_req) {
	fetch_request_release(req);
	return js_mkundef();
	}

	done = js_get(js, result, "done");
	value = js_get(js, result, "value");
	if (done == js_true) {
	ant_http_request_end(req->http_req);
	fetch_request_release(req);
	return js_mkundef();
	}

	if (!fetch_get_upload_chunk(value, &chunk, &chunk_len)) {
	ant_value_t reason = js_mkerr_typed(js, JS_ERR_TYPE, "fetch request body stream chunk must be a Uint8Array");
	ant_http_request_cancel(req->http_req);
	fetch_reject(req, fetch_rejection_reason(js, reason));
	fetch_request_release(req);
	return js_mkundef();
	}

	rc = ant_http_request_write(req->http_req, chunk, chunk_len);
	if (rc != 0) {
	ant_value_t reason = fetch_type_error(js, uv_strerror(rc));
	ant_http_request_cancel(req->http_req);
	fetch_reject(req, reason);
	fetch_request_release(req);
	return js_mkundef();
	}

	fetch_upload_schedule_next_read(req);
	fetch_request_release(req);
	return js_mkundef();
	}

	static void fetch_upload_schedule_next_read(fetch_request_t *req) {
	ant_t *js = req->js;

	ant_value_t next_p = 0;
	ant_value_t fulfill = 0;
	ant_value_t reject = 0;
	ant_value_t then_result = 0;

	if (!req \|\| !is_object_type(req->upload_reader)) return;
	next_p = rs_default_reader_read(js, req->upload_reader);
	req->upload_read_promise = next_p;

	fulfill = js_heavy_mkfun(js, fetch_upload_on_read, ANT_PTR(req));
	reject = js_heavy_mkfun(js, fetch_upload_on_reject, ANT_PTR(req));

	fetch_request_retain(req);
	then_result = js_promise_then(js, next_p, fulfill, reject);
	promise_mark_handled(then_result);
	}

	static void fetch_start_upload(fetch_request_t *req) {
	ant_t *js = req->js;

	ant_value_t stream = js_get_slot(req->request_obj, SLOT_REQUEST_BODY_STREAM);
	ant_value_t reader_args[1] = { stream };
	ant_value_t saved = js->new_target;
	ant_value_t reader = 0;

	if (!rs_is_stream(stream)) return;

	js->new_target = g_reader_proto;
	reader = js_rs_reader_ctor(js, reader_args, 1);
	js->new_target = saved;

	if (is_err(reader)) {
	if (req->http_req) ant_http_request_cancel(req->http_req);
	fetch_reject(req, fetch_rejection_reason(js, reader));
	if (!req->http_req) fetch_request_release(req);
	return;
	}

	req->upload_reader = reader;
	fetch_upload_schedule_next_read(req);
	}

	static void fetch_start_http(fetch_request_t *req) {
	request_data_t *request = request_get_data(req->request_obj);
	ant_http_request_options_t options = {0};
	ant_http_header_t *headers = NULL;
	char *url = NULL;
	int rc = 0;

	if (!request) {
	fetch_reject(req, fetch_type_error(req->js, "Invalid Request object"));
	fetch_request_release(req);
	return;
	}

	url = fetch_build_request_url(request);
	if (!url) {
	fetch_reject(req, fetch_type_error(req->js, "Invalid request URL"));
	fetch_request_release(req);
	return;
	}

	if (esm_is_data_url(url)) {
	free(url);
	fetch_handle_data_url(req);
	return;
	}
	if (!fetch_is_http_url(url)) {
	free(url);
	fetch_reject(req, fetch_type_error(req->js, "fetch only supports http:, https:, and data: URLs"));
	fetch_request_release(req);
	return;
	}

	headers = fetch_build_http_headers(req->request_obj);
	if (!headers) {
	free(url);
	fetch_reject(req, fetch_type_error(req->js, "out of memory"));
	fetch_request_release(req);
	return;
	}

	options.method = request->method;
	options.url = url;
	options.headers = headers;
	options.body = request->body_data;
	options.body_len = request->body_size;
	options.chunked_body = request->body_is_stream;

	rc = ant_http_request_start(
	uv_default_loop(), &options,
	fetch_http_on_response, fetch_http_on_body, fetch_http_on_complete,
	req, &req->http_req
	);

	ant_http_headers_free(headers);
	free(url);

	if (rc != 0) {
	fetch_reject(req, fetch_type_error(req->js, uv_strerror(rc)));
	fetch_request_release(req);
	return;
	}

	if (request->body_is_stream) fetch_start_upload(req);
	}

	static ant_value_t fetch_abort_listener(ant_t js, ant_value_t args, int nargs) {
	fetch_request_t req = (fetch_request_t )(uintptr_t)(size_t)js_getnum(js_get_slot(js->current_func, SLOT_DATA));
	ant_value_t signal = 0;
	ant_value_t reason = 0;

	if (!req \|\| req->aborted) return js_mkundef();
	req->aborted = true;
	signal = request_get_signal(req->request_obj);
	reason = abort_signal_get_reason(signal);

	if (req->http_req) ant_http_request_cancel(req->http_req);
	fetch_reject(req, reason);
	if (!req->http_req) fetch_request_release(req);

	return js_mkundef();
	}

	static ant_value_t js_fetch(ant_t js, ant_value_t args, int nargs) {
	ant_value_t input = (nargs >= 1) ? args[0] : js_mkundef();
	ant_value_t init = (nargs >= 2) ? args[1] : js_mkundef();
	ant_value_t promise = js_mkpromise(js);
	ant_value_t request_obj = 0;
	request_data_t *request = NULL;
	fetch_request_t *req = NULL;
	ant_value_t signal = 0;

	request_obj = request_create_from_input_init(js, input, init);
	if (is_err(request_obj)) {
	js_reject_promise(js, promise, fetch_rejection_reason(js, request_obj));
	return promise;
	}

	request = request_get_data(request_obj);
	if (!request) {
	js_reject_promise(js, promise, fetch_type_error(js, "Invalid Request object"));
	return promise;
	}

	req = calloc(1, sizeof(fetch_request_t));
	if (!req) {
	js_reject_promise(js, promise, fetch_type_error(js, "out of memory"));
	return promise;
	}

	req->js = js;
	req->promise = promise;
	req->request_obj = request_obj;
	req->response_obj = js_mkundef();
	req->abort_listener = js_mkundef();
	req->upload_reader = js_mkundef();
	req->upload_read_promise = js_mkundef();
	req->refs = 1;
	utarray_push_back(pending_requests, &req);

	signal = request_get_signal(request_obj);
	if (abort_signal_is_signal(signal)) {
	if (abort_signal_is_aborted(signal)) {
	fetch_reject(req, abort_signal_get_reason(signal));
	fetch_request_release(req);
	return promise;
	}

	req->abort_listener = js_heavy_mkfun(js, fetch_abort_listener, ANT_PTR(req));
	abort_signal_add_listener(js, signal, req->abort_listener);
	}

	if (request->has_body) request->body_used = true;
	fetch_start_http(req);
	return promise;
	}

	void init_fetch_module() {
	utarray_new(pending_requests, &ut_ptr_icd);
	js_set(rt->js, rt->js->global, "fetch", js_mkfun(js_fetch));
	}

	int has_pending_fetches(void) {
	return pending_requests && utarray_len(pending_requests) > 0;
	}

	void gc_mark_fetch(ant_t *js, gc_mark_fn mark) {
	if (!pending_requests) return;
	unsigned int len = utarray_len(pending_requests);

	for (unsigned int i = 0; i < len; i++) {
	fetch_request_t reqp = (fetch_request_t )utarray_eltptr(pending_requests, i);
	if (!reqp \|\| !*reqp) continue;
	mark(js, (*reqp)->promise);
	mark(js, (*reqp)->request_obj);
	mark(js, (*reqp)->response_obj);
	mark(js, (*reqp)->abort_listener);
	mark(js, (*reqp)->upload_reader);
	mark(js, (*reqp)->upload_read_promise);
	}
	}

File Metadata

Mime Type: text/x-c
Expires: Sun, May 3, 7:30 AM (15 h, 12 m)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 538490
Default Alt Text: fetch.c (20 KB)

fetch.cNo OneTemporaryActions

fetch.cView Options

File Metadata

Event Timeline

fetch.c
No OneTemporary
Actions

fetch.c
View Options