curran / curran/google-diff-match-patch
Replacing String with StringBuffer instances in patch_apply
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Performance
Type-Patch
- Dominant language
- Python
- Stars
- 17
- Forks
- 2
- PR merge metrics
- No merged PRs in 30d
Description
We used this DiffMatchPatch code extensively for tracking differences between
versions of database objects. Some of our calls can generate more than 25k
patch strings that need to be applied to large chunks of text. In this instance
we where seeing severe performance issues and inefficient memory management
(even on Java 6).
This patch replaces Strings with StringBuffer and implements more efficient
INSERT & DELETE operations which drastically reduces memory usage for large
text strings.
Original issue reported on code.google.com by chris.p....@gmail.com on 4 Oct 2011 at 4:37
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First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Review the attached diff_match_patch.java.patch against the Java implementation and inspect the patch_apply entry point first. Confirm that the proposed StringBuffer and INSERT/DELETE changes preserve patch application behavior while addressing the large-input memory and performance problems described in the issue.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- performance
- Issue type
- Refactor
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100