refactor: to use std libary func bytes.CutPrefix

[cuiweixie]

Summary by CodeRabbit

• Refactor
  • Simplified internal prefix handling using a more reliable standard approach, reducing custom logic.
• Bug Fixes
  • Added explicit validation when deriving keys with prefixes, preventing silent inconsistencies and surfacing issues earlier.
• Chores
  • Removed unused internal helper code related to prefix processing.

No user-facing behavior changes are expected under normal conditions; overall robustness and maintainability are improved.

[cuiweixie]

#25357
@aljo242

[coderabbitai]

📝 Walkthrough

Walkthrough

Replaced a custom prefix-stripping helper in PrefixIterator.Key with bytes.CutPrefix, adding an explicit presence check and panic on mismatch. Removed the unused helper. External behavior remains unchanged when the prefix is valid.

Changes

Cohort / File(s)	Summary
Prefix handling in PrefixIterator.Key store/prefix/store.go	Switched from custom stripPrefix to bytes.CutPrefix in Key(); added ok check and panic if prefix not found; removed stripPrefix helper.

Sequence Diagram(s)

sequenceDiagram
    participant C as Caller
    participant PI as PrefixIterator
    participant B as bytes.CutPrefix

    C->>PI: Key()
    PI->>B: CutPrefix(key, prefix)
    B-->>PI: (rest, ok)
    alt prefix present
        PI-->>C: return rest
    else prefix missing
        PI-->>C: panic("should not happen")
    end
    note over PI: Explicit validation replaces implicit assumption

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Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title clearly identifies the primary change (switching to bytes.CutPrefix) and therefore relates to the main changeset, but it contains a spelling error ("libary") and awkward phrasing ("to use", "func") that reduce clarity and polish.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

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📥 Commits

Reviewing files that changed from the base of the PR and between 9171179 and 70e20f0.

📒 Files selected for processing (1)

• store/prefix/store.go (1 hunks)

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• GitHub Check: Summary

🔇 Additional comments (2)

store/prefix/store.go (2)

166-169: LGTM! Good refactor to use standard library function.

The refactor to use bytes.CutPrefix is a good improvement that leverages the standard library. The explicit check for prefix presence with a panic on mismatch maintains the expected invariant while providing clearer error handling than the previous custom stripPrefix helper.

---

166-169: Panic is unreachable — prefix invariant holds.

newPrefixIterator sets pi.valid = parent.Valid() && bytes.HasPrefix(parent.Key(), prefix), and Next() clears pi.valid whenever iter becomes invalid or the key no longer has the prefix. Key() requires pi.valid before calling iter.Key(), so bytes.CutPrefix cannot fail under normal (single-threaded) iterator usage.

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[aljo242]

can you test and benchmark this

[cuiweixie]

can you test and benchmark this

 store git:(bytes.CutPrefix) go test ./...
?       cosmossdk.io/store      [no test files]
ok      cosmossdk.io/store/cache        (cached)
ok      cosmossdk.io/store/cachekv      (cached)
ok      cosmossdk.io/store/cachekv/internal     (cached)
ok      cosmossdk.io/store/cachemulti   (cached)
ok      cosmossdk.io/store/dbadapter    (cached)
ok      cosmossdk.io/store/gaskv        (cached)
ok      cosmossdk.io/store/iavl (cached)
ok      cosmossdk.io/store/internal/conv        (cached)
?       cosmossdk.io/store/internal/kv  [no test files]
ok      cosmossdk.io/store/internal/maps        0.010s
ok      cosmossdk.io/store/internal/proofs      (cached)
?       cosmossdk.io/store/internal/tree        [no test files]
ok      cosmossdk.io/store/listenkv     0.019s
ok      cosmossdk.io/store/mem  (cached)
?       cosmossdk.io/store/metrics      [no test files]
?       cosmossdk.io/store/mock [no test files]
ok      cosmossdk.io/store/prefix       0.021s
ok      cosmossdk.io/store/pruning      (cached)
ok      cosmossdk.io/store/pruning/types        (cached)
ok      cosmossdk.io/store/rootmulti    47.202s
ok      cosmossdk.io/store/snapshots    (cached)
ok      cosmossdk.io/store/snapshots/types      (cached)
ok      cosmossdk.io/store/streaming    (cached)
?       cosmossdk.io/store/streaming/abci       [no test files]
?       cosmossdk.io/store/streaming/abci/examples/file [no test files]
ok      cosmossdk.io/store/tracekv      0.019s
ok      cosmossdk.io/store/transient    (cached)
ok      cosmossdk.io/store/types        (cached)
?       cosmossdk.io/store/wrapper      [no test files]

benchmark:

package main

import (
	"bytes"
	"testing"
)

// 方法1：手动实现
func stripPrefix(key, prefix []byte) []byte {
	if len(key) < len(prefix) || !bytes.Equal(key[:len(prefix)], prefix) {
		panic("should not happen")
	}
	return key[len(prefix):]
}

// 方法2：使用 bytes.CutPrefix
func stripPrefixBuiltin(key, prefix []byte) []byte {
	result, ok := bytes.CutPrefix(key, prefix)
	if !ok {
		panic("should not happen")
	}
	return result
}

// Benchmark 测试
func BenchmarkStripPrefix(b *testing.B) {
	key := []byte("prefix_some_long_key_data_here")
	prefix := []byte("prefix_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefix(key, prefix)
	}
}

func BenchmarkStripPrefixBuiltin(b *testing.B) {
	key := []byte("prefix_some_long_key_data_here")
	prefix := []byte("prefix_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefixBuiltin(key, prefix)
	}
}

// 测试不同长度的 prefix
func BenchmarkStripPrefixShort(b *testing.B) {
	key := []byte("a_some_long_key_data_here")
	prefix := []byte("a_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefix(key, prefix)
	}
}

func BenchmarkStripPrefixBuiltinShort(b *testing.B) {
	key := []byte("a_some_long_key_data_here")
	prefix := []byte("a_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefixBuiltin(key, prefix)
	}
}

func BenchmarkStripPrefixLong(b *testing.B) {
	key := []byte("very_long_prefix_here_some_long_key_data_here")
	prefix := []byte("very_long_prefix_here_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefix(key, prefix)
	}
}

func BenchmarkStripPrefixBuiltinLong(b *testing.B) {
	key := []byte("very_long_prefix_here_some_long_key_data_here")
	prefix := []byte("very_long_prefix_here_")

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = stripPrefixBuiltin(key, prefix)
	}
}

BenchmarkStripPrefix
BenchmarkStripPrefix-10                	505638128	         2.277 ns/op
BenchmarkStripPrefixBuiltin
BenchmarkStripPrefixBuiltin-10         	512019571	         2.286 ns/op
BenchmarkStripPrefixShort
BenchmarkStripPrefixShort-10           	478129240	         2.518 ns/op
BenchmarkStripPrefixBuiltinShort
BenchmarkStripPrefixBuiltinShort-10    	484700299	         2.421 ns/op
BenchmarkStripPrefixLong
BenchmarkStripPrefixLong-10            	371604224	         3.245 ns/op
BenchmarkStripPrefixBuiltinLong
BenchmarkStripPrefixBuiltinLong-10     	369011395	         3.267 ns/op
PASS

it's almost equal. code logic is almost equal too.