Zipdownload: add ZipStream support for large exports

.ci/run_browser_tests.sh

@@ -63,3 +63,10 @@ TESTS_MODE=tablet vendor/bin/phpunit -c tests/Browser/phpunit.xml --fail-on-warn
 # Mobile mode tests are unreliable on Github Actions
 # echo "TESTS_MODE: PHONE"
 # TESTS_MODE=phone vendor/bin/phpunit -c tests/Browser/phpunit.xml --fail-on-warning --fail-on-risky --display-deprecations --exclude-group=failsonga-phone
+
+# Only run tests for ZipStream if it's supported - 64-bit PHP
+if php -r 'exit(PHP_INT_SIZE >= 8 ? 0 : 1);'; then
+	echo "TESTS_MODE: DESKTOP with zipstream"
+	composer require $COMPOSER_ARGS -n 'maennchen/zipstream-php:^3.0'
+	TESTS_MODE=desktop vendor/bin/phpunit -c tests/Browser/phpunit.xml --fail-on-warning --fail-on-risky --display-deprecations plugins/zipdownload/tests/Browser
+fi

.github/workflows/ci.yml

@@ -71,6 +71,7 @@ jobs:
         run: |
             composer require "kolab/net_ldap3:~1.1.1" --no-update
             composer require "laravel/dusk:^8.3" --no-update
+            composer require "maennchen/zipstream-php:^3.0" --no-update
 
       - name: Install dependencies
         run: composer install --prefer-dist --no-interaction --no-progress

composer.json

@@ -71,7 +71,8 @@
     "suggest": {
         "ext-sodium": "Support EdDSA (Ed25519) signatures (OAuth)",
         "bjeavons/zxcvbn-php": "^1.0 required for Zxcvbn password strength driver",
-        "kolab/net_ldap3": "~1.1.4 required for connecting to LDAP"
+        "kolab/net_ldap3": "~1.1.4 required for connecting to LDAP",
+        "maennchen/zipstream-php": "^3.0 optional for larger zip support in zipdownload plugin"
     },
     "repositories": [
         {

plugins/zipdownload/README

@@ -8,6 +8,18 @@ Requirements
 ============
 * php_zip extension (including ZipArchive class)
 
+Optional
+========
+* maennchen/zipstream-php version 3.x (64-bit only)
+
+With this optional package installed, emails will be streamed directly
+from the storage backend, compressed in chunks, and sent to the web client
+without using any temporary disk space. The zipdownload_selection config
+setting may be increased significantly if desired.
+
+Without this optional package, temporary disk space equal to about 130% of
+the zipdownload_selection setting might be used when emails are downloaded.
+
 License
 =======
 This plugin is released under the GNU General Public License Version 3

plugins/zipdownload/config.inc.php.dist

@@ -12,7 +12,8 @@ $config['zipdownload_attachments'] = 1;
 // Zip selection of mail messages
 // This option enables downloading of multiple messages as one zip archive.
 // The number or string value specifies maximum total size of all messages
-// in the archive (not the size of the archive itself).
+// in the archive (not the size of the archive itself). Please see the
+// README file for more details before making large changes to this limit.
 $config['zipdownload_selection'] = '50MB';
 
 // Charset to use for filenames inside the zip