Client-side vs server-side hooks in Git - Performance Comparison

Time Complexity: Client-side vs server-side hooks

O(n)

Understanding Time Complexity

We want to understand how the time it takes to run Git hooks changes as the number of commits or pushes grows.

Which hook type--client-side or server-side--scales better with more activity?

Scenario Under Consideration

Analyze the time complexity of these Git hook examples.

# Client-side pre-commit hook example
#!/bin/sh
files=$(git diff --cached --name-only)
for file in $files; do
  # Run lint check on each file
  lint-check "$file"
done

# Server-side pre-receive hook example
#!/bin/sh
while read oldrev newrev refname; do
  # Run tests on the pushed commits
  run-tests "$oldrev" "$newrev"
done

The client-side hook checks each changed file before commit. The server-side hook checks all commits in a push.

Identify Repeating Operations

Look for loops or repeated checks in the hooks.

• Primary operation: Loop over changed files (client-side) or commits (server-side).
• How many times: Number of changed files in commit or number of commits in push.

How Execution Grows With Input

More changed files or commits mean more checks.

Input Size (n)	Approx. Operations
10 files/commits	10 lint or test runs
100 files/commits	100 lint or test runs
1000 files/commits	1000 lint or test runs

Pattern observation: The time grows directly with the number of files or commits checked.

Final Time Complexity

Time Complexity: O(n)

This means the time to run hooks grows linearly with the number of files or commits processed.

Common Mistake

[X] Wrong: "Hooks always run instantly no matter how many files or commits there are."

[OK] Correct: Each file or commit adds work, so more changes mean more time spent running hooks.

Interview Connect

Understanding how hook execution time grows helps you design efficient workflows and avoid slowdowns as projects grow.

Self-Check

"What if the client-side hook ran checks only on staged files instead of all changed files? How would the time complexity change?"