serialize and deserialize entire Response object when relaying fetch() calls to other contexts using sendMessage

3 files changed, 135 insertions, 37 deletions

diff --git a/html/install.js b/html/install.js
index fddee5d..a066b9b 100644
--- a/html/install.js
+++ b/html/install.js
@@ -51,6 +51,8 @@
 #FROM common/misc.js       IMPORT sha256_async AS compute_sha256
 #FROM common/jsonschema.js IMPORT haketilo_validator, haketilo_schemas
 
+#FROM html/repo_query_cacher_client.js IMPORT indirect_fetch
+
 const coll = new Intl.Collator();
 
 /*
@@ -104,6 +106,9 @@ async function init_work() {
     };
 
     work.err = function (error, user_message) {
+	if (!this.is_ok)
+	    return;
+
 	if (error)
 	    console.error("Haketilo:", error);
 	work.is_ok = false;
@@ -171,35 +176,40 @@ function InstallView(tab_id, on_view_show, on_view_hide) {
 	const url = ver ?
 	      `${this.repo_url}${item_type}/${id}/${ver.join(".")}` :
 	      `${this.repo_url}${item_type}/${id}.json`;
-	const response =
-	      await browser.tabs.sendMessage(tab_id, ["repo_query", url]);
-	if (!work.is_ok)
-	    return;
 
-	if ("error" in response) {
-	    return work.err(response.error,
-			    "Failure to communicate with repository :(");
+
+	try {
+	    var response = await indirect_fetch(tab_id, url);
+	} catch(e) {
+	    return work.err(e, "Failure to communicate with repository :(");
 	}
 
+	if (!work.is_ok)
+	    return;
+
 	if (!response.ok) {
 	    return work.err(null,
 			    `Repository sent HTTP code ${response.status} :(`);
 	}
 
-	if ("error_json" in response) {
-	    return work.err(response.error_json,
-			    "Repository's response is not valid JSON :(");
+	try {
+	    var json = await response.json();
+	} catch(e) {
+	    return work.err(e, "Repository's response is not valid JSON :(");
 	}
 
+	if (!work.is_ok)
+	    return;
+
 	const captype = item_type[0].toUpperCase() + item_type.substring(1);
 
 	const $id =
 	      `https://hydrilla.koszko.org/schemas/api_${item_type}_description-1.0.1.schema.json`;
 	const schema = haketilo_schemas[$id];
-	const result = haketilo_validator.validate(response.json, schema);
+	const result = haketilo_validator.validate(json, schema);
 	if (result.errors.length > 0) {
 	    const reg = new RegExp(schema.allOf[2].properties.$schema.pattern);
-	    if (response.json.$schema && !reg.test(response.json.$schema)) {
+	    if (json.$schema && !reg.test(json.$schema)) {
 		const msg = `${captype} ${item_id_string(id, ver)} was served using unsupported Hydrilla API version. You might need to update Haketilo.`;
 		return work.err(result.errors, msg);
 	    }
@@ -208,14 +218,14 @@ function InstallView(tab_id, on_view_show, on_view_hide) {
 	    return work.err(result.errors, msg);
 	}
 
-	const scripts = item_type === "resource" && response.json.scripts;
-	const files = response.json.source_copyright.concat(scripts || []);
+	const scripts = item_type === "resource" && json.scripts;
+	const files = json.source_copyright.concat(scripts || []);
 
 	if (item_type === "mapping") {
-	    for (const res_ref of Object.values(response.json.payloads || {}))
+	    for (const res_ref of Object.values(json.payloads || {}))
 		process_item(work, "resource", res_ref.identifier);
 	} else {
-	    for (const res_ref of (response.json.dependencies || []))
+	    for (const res_ref of (json.dependencies || []))
 		process_item(work, "resource", res_ref.identifier);
 	}
 
@@ -234,8 +244,8 @@ function InstallView(tab_id, on_view_show, on_view_hide) {
 	    const msg = "Error accessing Haketilo's internal database :(";
 	    return work.err(e, msg);
 	}
-	if (!db_def || db_def.version < response.json.version)
-	    work.result.push({def: response.json, db_def});
+	if (!db_def || db_def.version < json.version)
+	    work.result.push({def: json, db_def});
 
 	if (--work.waiting === 0)
 	    work.resolve_cb(work.result);
@@ -320,14 +330,9 @@ function InstallView(tab_id, on_view_show, on_view_hide) {
 		return work.err(null, msg);
 	    }
 
-	    try {
-		var text = await response.text();
-		if (!work.is_ok)
-		    return;
-	    } catch(e) {
-		const msg = "Repository's response is not valid text :(";
-		return work.err(e, msg);
-	    }
+	    const text = await response.text();
+	    if (!work.is_ok)
+		return;
 
 	    const digest = await compute_sha256(text);
 	    if (!work.is_ok)
diff --git a/html/repo_query.js b/html/repo_query.js
index 601a0aa..97f60ac 100644
--- a/html/repo_query.js
+++ b/html/repo_query.js
@@ -49,6 +49,8 @@
 #FROM html/install.js      IMPORT InstallView
 #FROM common/jsonschema.js IMPORT haketilo_validator, haketilo_schemas
 
+#FROM html/repo_query_cacher_client.js IMPORT indirect_fetch
+
 const coll = new Intl.Collator();
 
 function ResultEntry(repo_entry, mapping_ref) {
@@ -76,36 +78,42 @@ function RepoEntry(query_view, repo_url) {
 
     this.repo_url_label.innerText = repo_url;
 
-    const query_results = async () => {
-	const msg = [
-	    "repo_query",
-	    `${repo_url}query?url=${encodeURIComponent(query_view.url)}`
-	];
-	const response = await browser.tabs.sendMessage(query_view.tab_id, msg);
+    const encoded_queried_url = encodeURIComponent(query_view.url);
+    const query_url = `${repo_url}query?url=${encoded_queried_url}`;
 
-	if ("error" in response)
+    const query_results = async () => {
+	try {
+	    var response = await indirect_fetch(query_view.tab_id, query_url);
+	} catch(e) {
+	    console.error("Haketilo:", e);
 	    throw "Failure to communicate with repository :(";
+	}
 
 	if (!response.ok)
 	    throw `Repository sent HTTP code ${response.status} :(`;
-	if ("error_json" in response)
+
+	try {
+	    var json = await response.json();
+	} catch(e) {
+	    console.error("Haketilo:", e);
 	    throw "Repository's response is not valid JSON :(";
+	}
 
 	const $id =
 	      `https://hydrilla.koszko.org/schemas/api_query_result-1.0.1.schema.json`;
 	const schema = haketilo_schemas[$id];
-	const result = haketilo_validator.validate(response.json, schema);
+	const result = haketilo_validator.validate(json, schema);
 	if (result.errors.length > 0) {
 	    console.error("Haketilo:", result.errors);
 
 	    const reg = new RegExp(schema.properties.$schema.pattern);
-	    if (response.json.$schema && !reg.test(response.json.$schema))
+	    if (json.$schema && !reg.test(json.$schema))
 		throw "Results were served using unsupported Hydrilla API version. You might need to update Haketilo.";
 
 	    throw "Results were served using a nonconforming response format.";
 	}
 
-	return response.json.mappings;
+	return json.mappings;
     }
 
     const populate_results = async () => {
diff --git a/html/repo_query_cacher_client.js b/html/repo_query_cacher_client.js
new file mode 100644
index 0000000..b7f49e9
--- /dev/null
+++ b/html/repo_query_cacher_client.js
@@ -0,0 +1,85 @@
+/**
+ * This file is part of Haketilo.
+ *
+ * Function: Making requests to remote repositories through a response cache in
+ *           operating in the content script of a browser tab.
+ *
+ * Copyright (C) 2022 Wojtek Kosior <koszko@koszko.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you
+ * may distribute forms of that code without the copy of the GNU
+ * GPL normally required by section 4, provided you include this
+ * license notice and, in case of non-source distribution, a URL
+ * through which recipients can access the Corresponding Source.
+ * If you modify file(s) with this exception, you may extend this
+ * exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * As a special exception to the GPL, any HTML file which merely
+ * makes function calls to this code, and for that purpose
+ * includes it by reference shall be deemed a separate work for
+ * copyright law purposes. If you modify this code, you may extend
+ * this exception to your version of the code, but you are not
+ * obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * I, Wojtek Kosior, thereby promise not to sue for violation of this file's
+ * license. Although I request that you do not make use of this code in a
+ * proprietary program, I am not going to enforce this in court.
+ */
+
+#FROM common/browser.js IMPORT browser
+
+/*
+ * This is a complementary function to error_data_jsonifiable() in
+ * common/misc.js.
+ */
+function error_from_jsonifiable_data(jsonifiable) {
+    const arg_props = ["message", "fileName", "lineNumber"];
+    return new window[jsonifiable.name](...arg_props.map(p => jsonifiable[p]));
+}
+
+/*
+ * Make it possible to recover a Response object. This is a complementary
+ * function to response_data_jsonifiable() in background/CORS_bypass_server.js.
+ */
+function response_from_jsonifiable_data(jsonifiable) {
+    const body = jsonifiable.body, body_len = body.length / 2;
+    const body_buf = new Uint8Array(body_len);
+
+    for (let i = 0; i < body_len; i++)
+	body_buf[i] = parseInt(`0x${body.substring(i * 2, i * 2 + 2)}`);
+
+    const init = {
+	status:     jsonifiable.status,
+	statusText: jsonifiable.statusText,
+	headers:    new Headers(jsonifiable.headers)
+    };
+
+    return new Response(body_buf, init);
+}
+
+async function indirect_fetch(tab_id, url) {
+    const msg = ["repo_query", url];
+    const jsonifiable = await browser.tabs.sendMessage(tab_id, msg);
+
+    if ("error" in jsonifiable)
+	throw error_from_jsonifiable_data(jsonifiable);
+
+    return response_from_jsonifiable_data(jsonifiable);
+}
+#EXPORT indirect_fetch