[OutOfMemoryError] Fix OOM at `LogEncrypt.encrypt(...)` #28

ParaskP7 · 2025-09-09T17:13:46Z

Fixes: #16
Closes: AINFRA-1217
(Internal) Discussions: p1754667446732699-slack-C030U03RC8Y + p1757585328963649-slack-C030U03RC8Y

Description

This PR resolves a long standing OutOfMemory (OOM) error when using this library alongside logs that are of large size.

FYI: Actually, this change resolves a couple more (potential) issues like:

ANRs when the library tries to process large logs (no matter if that results in an OOM or not). See for example: AINFRA-1182
InvalidRequests when the library is successful in processing large logs (10MB+), but the API respond with 400 just because of the MAX_FILE_SIZE_IN_BYTES restriction on WPCOM_JSON_API_Encrypted_Logs_Endpoint.

Overall, this change:

Introduces a MAX_LOG_FILE_SIZE of 5MB, just because the resulting encrypted text is about 1.4 larger per MB of a log file, resulting in a final max of about 7MB that is sent to the API. We could have used 6MB as the max log file size, which would result in 8.4MB of encrypted text sent, but it is better to keep enough buffer just in case, and this way, to safeguard ourselves from any InvalidRequest responses from the API.
Based on this MAX_LOG_FILE_SIZE of 5MB, if a log's file size exceeds this max, it is truncated to that 5MB of size, skipping the beginning of the log and only keep the more recent logs.

Testing Steps

Using the DOAndroid project, update automattic-encryptedlogging to 28-f19c0d92473042e5976c92cd7b88cf641456691a (version which is based on this PR's latest commit) and make sure that encrypted logging could work with logs of large size.

Note

I would first advise you to replicate an OOM using your physical/virtual device of choice. To do so, update automattic-encryptedlogging to 28-a16584d1c883c758c29e8e40f8bba0c1320ff567 instead. This commit skips the uploading of the encrypted log to the API, and just handles the encryption part.

Tip

FYI: You could use the below DOAndroid patch, which add the Fill The Log development option into the Developer screen of the app and on click adds 10000 log lines (or else 4MB worth of logs). Adding another 0 to that numberOfLogs val will give you 40MB instead, use what you need:

patch

Subject: [PATCH] Tmp: Assemble release on ci for pr
---
Index: app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperAction.kt
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperAction.kt b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperAction.kt
--- a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperAction.kt	(revision f2622054d961b58bf298d4ab91049be79c19a87b)
+++ b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperAction.kt	(date 1757609295757)
@@ -14,6 +14,8 @@
 
     data object CrashApp : DeveloperAction()
 
+    data object FillLog : DeveloperAction()
+
     data object DeleteAllJournals : DeveloperAction()
 
     data object ReloadCurrentMasterKeyStorage : DeveloperAction()
Index: app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperFragment.kt
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperFragment.kt b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperFragment.kt
--- a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperFragment.kt	(revision f2622054d961b58bf298d4ab91049be79c19a87b)
+++ b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperFragment.kt	(date 1757609295757)
@@ -141,6 +141,20 @@
                 }
             }
             DeveloperAction.CrashApp -> throw Exception("Developer caused a crash!")
+            DeveloperAction.FillLog -> {
+                val numberOfLogs = 10000 // 4MB
+                (0..numberOfLogs).forEachIndexed { index, _ ->
+                    DOLogger.d(TAG, "Filling log line $index " +
+                            "[FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST " +
+                            "FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST " +
+                            "FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST " +
+                            "FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST FILL LOG TEST]"
+                    )
+                    if (index % (numberOfLogs/5) == 0) {
+                        Toast.makeText(context, "Filled $index log lines", Toast.LENGTH_SHORT).show()
+                    }
+                }
+            }
             DeveloperAction.DeleteAllJournals -> deleteAllJournals()
             DeveloperAction.ReloadCurrentMasterKeyStorage -> viewModel.reloadMasterKeyStorage()
             DeveloperAction.EnterMasterKey -> enterMasterKey()
Index: app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperComponentList.kt
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperComponentList.kt b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperComponentList.kt
--- a/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperComponentList.kt	(revision f2622054d961b58bf298d4ab91049be79c19a87b)
+++ b/app/src/main/java/com/dayoneapp/dayone/main/settings/DeveloperComponentList.kt	(date 1757609295757)
@@ -413,6 +413,10 @@
         title = { Text(text = stringResource(R.string.crash_app)) },
         onClick = { onClick(DeveloperAction.CrashApp) },
     )
+    SettingItem(
+        title = { Text(text = stringResource(R.string.fill_log)) },
+        onClick = { onClick(DeveloperAction.FillLog) },
+    )
     if (BuildConfig.DEBUG) {
         SettingItem(
             title = { Text(text = stringResource(R.string.purge_welcome_entries)) },
Index: app/src/main/res/values/strings.xml
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
--- a/app/src/main/res/values/strings.xml	(revision f2622054d961b58bf298d4ab91049be79c19a87b)
+++ b/app/src/main/res/values/strings.xml	(date 1757609295758)
@@ -881,6 +881,7 @@
     <string name="reset_passive_message_settings">Reset Passive Messages Settings</string>
     <string name="reset_today_tooltip_message_settings">Reset Today Tooltip Message Settings</string>
     <string name="crash_app">Crash The App</string>
+    <string name="fill_log">Fill The Log</string>
     <string name="enable_premium_dev">Enable Premium Dev</string>
     <string name="should_loggedin_premium_dev">You Should be Logged In To Enable Premium Dev</string>
     <string name="purge_welcome_entries">Purge possible welcome entries</string>

PS: Don't forget to use the Device Explorer to check on the actual size of the log right before you cause a crash (using another Crash The App development option from the Developer screen of the app. File log path: /data/data/com.dayoneapp.dayone.debug/files/dayonelogs/com.dayoneapp.dayone.debug YYYY-MM-DD.log

Follow the below generic steps with a log of 2MB, 10MB, 50MB and 200MB file size:

Using App Inspection from AS find the encrypted-logging.db and its sole EncryptedLogModel table. Notice that the table is empty, there are no log to be sent.
Make the app crash. Using DOAndroid for example, you could navigate to Settings -> Developer and then click Crash The App.
You might now notice a new db entry within App Inspection from AS on that DETACHED app (or not, it depends). Now, switch to the ATTACHED app and notice the db empty. This is because this db entry/log has been already sent to Sentry already, on app start and after the app crashed. To really notice the entry, trying crashing the app again, this time put the device on offline mode first. Doing that you'll be able to see the entry on the db, even when switching to the newly created ATTACHED app.
Open Sentry and navigate to Issues. Find the project you're testing for (for example day-one-android or/and pocket-casts-android) and check the latest debug exceptions. Using DOAndroid for example, you could search for Developer caused a crash! and check the latest crash. Now navigate at the bottom and check the uuid. Verify it is the same UUID that you saw on that db entry before.
Open Read Encrypted Logs, copy-paste that UUID into Log UUID, click View and make sure you can read the newly uploaded and now decrypted log.

For a log of specific size (see above) expect to get the following results, all without any OOM, or ANR, or an InvalidRequest response from the API, and the app should launch instantly, that is, after the crash, without any delay:

2MB:
- ℹ️ Enqueueing sending encrypted logs. Log file: com.dayoneapp.dayone.debug YYYY-MM-DD.log, 2.00mb
- ℹ️ The size of encrypted text with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is: 2.80mb
- ℹ️ Successfully uploaded encrypted log with uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
10MB:
- ℹ️ Enqueueing sending encrypted logs. Log file: com.dayoneapp.dayone.debug YYYY-MM-DD.log, 10.00mb
- ⚠️ Log file with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is too big (10.00mb), max allowed log file size is 5.00mb; log file got truncated.
- ℹ️ The size of encrypted text with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is: 7.00mb
- ℹ️ Successfully uploaded encrypted log with uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
50MB:
- ℹ️ Enqueueing sending encrypted logs. Log file: com.dayoneapp.dayone.debug YYYY-MM-DD.log, 50.00mb
- ⚠️ Log file with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is too big (50.00mb), max allowed log file size is 5.00mb; log file got truncated.
- ℹ️ The size of encrypted text with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is: 7.00mb
- ℹ️ Successfully uploaded encrypted log with uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
200MB:
- ℹ️ Enqueueing sending encrypted logs. Log file: com.dayoneapp.dayone.debug YYYY-MM-DD.log, 200.00mb
- ⚠️ Log file with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is too big (200.00mb), max allowed log file size is 5.00mb; log file got truncated.
- ℹ️ The size of encrypted text with uuid XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX is: 7.00mb
- ℹ️ Successfully uploaded encrypted log with uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

Copilot

Pull Request Overview

This PR fixes an OutOfMemoryError occurring in the LogEncrypt.encrypt(...) method by temporarily disabling the actual log upload functionality while preserving the encryption logging for debugging purposes.

Commented out the actual REST client upload call to prevent OOM issues
Added debug logging to track successful encryption operations
Modified success message to reflect that uploads are being handled rather than actually uploaded

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt

FYI: This change is for debugging purposes so that to avoid uploading log files that are too big, and until we figure out how big a log file should be to cause this OOM problem. Then, to try to fix the problem and see if 'logEncrypter.encrypt(...)' could now handle such big log files.

Copilot

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt

...gging/src/main/kotlin/com/automattic/encryptedlogging/model/encryptedlogging/LogEncrypter.kt

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt

FYI: This 5MB max logs size limit is both arbitrary and empirical because it seems that for (at least) some standard devices, large logs files of 100MB+ can easily cause OOM. Also, this 5MB max logs size limit is chosen because the API accepts logs up to 10MB, but we leave enough headroom for encoding overhead. PS: It is worth to note that we could apply a different kind of a solution (better one), like streaming encryption or chunked processing. But, I don't think it is worth it, nor I think it is worth sending such large log files to the API.

…art" This reverts commit a16584d.

FYI: Even after fixing the logs size problem during encryption, if the file is too big (200MB+), just because of the 'file.readText()', which tries to read the entire file into memory as string, another OOM problem occurs, this time before the encryption logic even runs. By file size checking and truncating the file to the last 10MB (if too big), we are avoiding this OOM issue. The current approach: - Creates a temp file with only the last 10MB of data. - Reads the temp file content and returns it. - Cleans up the temp file in the finally block. - Leaves the original file completely untouched.

This reverts commit 6990d7c

Copilot

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt

Now that the initial fix (6990d7c) got reverted (b007944) there is no point referring to a 'MAX_IN_MEMORY_SIZE' constant, but rather a 'MAX_LOG_FILE_SIZE' constant which also adheres to what the API accepts, which is logs up to 10MB. FYI: Although the API accepts logs up to 10MB, we use 5MB to leave enough room for the encryption overhead (and in order to avoid 400 failure with upload turning into invalid requests). PS: Actually, while testing this solution I also tried working with 9MB, then 8MB, then 7MB, all resulting in 400 ('InvalidRequest'). Only when I tried using 6MB the API started accepting the truncated encrypted log. As such, an in order to give enough buffer, I set the final value to 5MB, just in case 6MB isn't enough for every case.

harrytmthy · 2025-09-11T16:59:26Z

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt

-            val encryptedText = logEncrypter.encrypt(text = encryptedLog.file.readText(), uuid = encryptedLog.uuid)
+        val encryptedText = if (encryptedLog.file.length() <= MAX_LOG_FILE_SIZE) {
+            logEncrypter.encrypt(
+                text = encryptedLog.file.readText(),


We cap the file at 5 MB but still load it into memory with readText(). This inflates size (UTF-16 + base64) and may still cause OOM on low-RAM devices. Could LogEncrypter.encrypt support ByteArray or InputStream for streaming/chunked encryption to avoid building a full String?

We cap the file at 5 MB but still load it into memory with readText(). This inflates size (UTF-16 + base64) and may still cause OOM on low-RAM devices.

That's true @harrytmthy and thanks for the note here! 💯

Could LogEncrypter.encrypt support ByteArray or InputStream for streaming/chunked encryption to avoid building a full String?

We could, we'll try this first, since the API anyway doesn't accept encrypted log files larger than 10MB and take it from there. 👍

ParaskP7 · 2025-09-16T10:48:26Z

👋 @wzieba just a friendly reminder about this! 🙏

wzieba

LGTM, leaving one minor nitpick

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/utils/Utils.kt

PR Comment: #28 #discussion_r2355022277 Co-authored-by: Wojciech Zięba <wojtek.zieba@automattic.com>

ParaskP7 · 2025-09-18T08:50:11Z

Thanks for reviewing/testing and leaving your suggestions on this @wzieba , much appreciated! 🙇 ❤️ 🚀

ParaskP7 requested a review from Copilot September 9, 2025 17:13

ParaskP7 added the bug Something isn't working label Sep 9, 2025

Copilot AI reviewed Sep 9, 2025

View reviewed changes

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt Outdated Show resolved Hide resolved

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt Outdated Show resolved Hide resolved

ParaskP7 force-pushed the fix/oom-at-log-encrypter-encrypt branch 6 times, most recently from 8c6bb2f to 5e85f84 Compare September 11, 2025 13:10

ParaskP7 requested a review from Copilot September 11, 2025 13:45

Copilot AI reviewed Sep 11, 2025

View reviewed changes

ParaskP7 added 3 commits September 11, 2025 16:48

Revert "Tmp: Don't upload encrypted log, just handle the encryption p…

b89f3c3

…art" This reverts commit a16584d.

ParaskP7 force-pushed the fix/oom-at-log-encrypter-encrypt branch from 5e85f84 to 7ae6f7d Compare September 11, 2025 13:49

Revert "Fix: Add logs size limit and pre-trip logs before encrypting"

b007944

This reverts commit 6990d7c

ParaskP7 force-pushed the fix/oom-at-log-encrypter-encrypt branch 4 times, most recently from 16c06ca to 4a7c828 Compare September 11, 2025 15:03

ParaskP7 requested a review from Copilot September 11, 2025 15:23

Copilot AI reviewed Sep 11, 2025

View reviewed changes

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt Outdated Show resolved Hide resolved

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/store/EncryptedLogStore.kt Outdated Show resolved Hide resolved

ParaskP7 force-pushed the fix/oom-at-log-encrypter-encrypt branch from 4a7c828 to a999320 Compare September 11, 2025 15:27

Debug: Check on the size of the encrypted text right before upload

f19c0d9

ParaskP7 force-pushed the fix/oom-at-log-encrypter-encrypt branch from 9c1878e to f19c0d9 Compare September 11, 2025 15:45

ParaskP7 marked this pull request as ready for review September 11, 2025 16:51

ParaskP7 requested a review from wzieba September 11, 2025 16:51

harrytmthy reviewed Sep 11, 2025

View reviewed changes

wzieba approved these changes Sep 17, 2025

View reviewed changes

encryptedlogging/src/main/kotlin/com/automattic/encryptedlogging/utils/Utils.kt Show resolved Hide resolved

Refactor: Remove unnecessary internal keyword on utils functions

ae25826

PR Comment: #28 #discussion_r2355022277 Co-authored-by: Wojciech Zięba <wojtek.zieba@automattic.com>

ParaskP7 merged commit d7fc023 into trunk Sep 18, 2025
7 checks passed

ParaskP7 mentioned this pull request Sep 18, 2025

Out Of Memory at com.automattic.encryptedlogging.model.encryptedlogging.LogEncrypter.encrypt #16

Closed

[OutOfMemoryError] Fix OOM at LogEncrypt.encrypt(...) #28

[OutOfMemoryError] Fix OOM at LogEncrypt.encrypt(...) #28

Uh oh!

Conversation

ParaskP7 commented Sep 9, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Description

Testing Steps

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Uh oh!

Uh oh!

Uh oh!

harrytmthy Sep 11, 2025

Choose a reason for hiding this comment

Uh oh!

ParaskP7 Sep 11, 2025

Choose a reason for hiding this comment

Uh oh!

ParaskP7 commented Sep 16, 2025

Uh oh!

wzieba left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

ParaskP7 commented Sep 18, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

[OutOfMemoryError] Fix OOM at `LogEncrypt.encrypt(...)` #28

[OutOfMemoryError] Fix OOM at `LogEncrypt.encrypt(...)` #28

ParaskP7 commented Sep 9, 2025 •

edited

Loading