From 8111b9dda5ad21c7da44f8ab563f2358126d95a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Mon, 11 Mar 2019 17:01:47 +0200
Subject: [PATCH] ethdb, trie: tiny API tidy-up from the database rework pr

---
 ethdb/leveldb/leveldb.go   | 80 +++++++++++++++++++-------------------
 ethdb/memorydb/memorydb.go | 70 ++++++++++++++++-----------------
 trie/proof_test.go         | 10 ++---
 trie/trie_test.go          |  2 +-
 4 files changed, 81 insertions(+), 81 deletions(-)

diff --git a/ethdb/leveldb/leveldb.go b/ethdb/leveldb/leveldb.go
index 11bba6b08..f730887d2 100644
--- a/ethdb/leveldb/leveldb.go
+++ b/ethdb/leveldb/leveldb.go
@@ -38,27 +38,27 @@ import (
 )
 
 const (
-	// leveldbDegradationWarnInterval specifies how often warning should be printed
-	// if the leveldb database cannot keep up with requested writes.
-	leveldbDegradationWarnInterval = time.Minute
+	// degradationWarnInterval specifies how often warning should be printed if the
+	// leveldb database cannot keep up with requested writes.
+	degradationWarnInterval = time.Minute
 
-	// leveldbMinCache is the minimum amount of memory in megabytes to allocate to
-	// leveldb read and write caching, split half and half.
-	leveldbMinCache = 16
+	// minCache is the minimum amount of memory in megabytes to allocate to leveldb
+	// read and write caching, split half and half.
+	minCache = 16
 
-	// leveldbMinHandles is the minimum number of files handles to allocate to the
-	// open database files.
-	leveldbMinHandles = 16
+	// minHandles is the minimum number of files handles to allocate to the open
+	// database files.
+	minHandles = 16
 
 	// metricsGatheringInterval specifies the interval to retrieve leveldb database
 	// compaction, io and pause stats to report to the user.
 	metricsGatheringInterval = 3 * time.Second
 )
 
-// LevelDBDatabase is a persistent key-value store. Apart from basic data storage
+// Database is a persistent key-value store. Apart from basic data storage
 // functionality it also supports batch writes and iterating over the keyspace in
 // binary-alphabetical order.
-type LevelDBDatabase struct {
+type Database struct {
 	fn string      // filename for reporting
 	db *leveldb.DB // LevelDB instance
 
@@ -78,13 +78,13 @@ type LevelDBDatabase struct {
 
 // New returns a wrapped LevelDB object. The namespace is the prefix that the
 // metrics reporting should use for surfacing internal stats.
-func New(file string, cache int, handles int, namespace string) (*LevelDBDatabase, error) {
+func New(file string, cache int, handles int, namespace string) (*Database, error) {
 	// Ensure we have some minimal caching and file guarantees
-	if cache < leveldbMinCache {
-		cache = leveldbMinCache
+	if cache < minCache {
+		cache = minCache
 	}
-	if handles < leveldbMinHandles {
-		handles = leveldbMinHandles
+	if handles < minHandles {
+		handles = minHandles
 	}
 	logger := log.New("database", file)
 	logger.Info("Allocated cache and file handles", "cache", common.StorageSize(cache*1024*1024), "handles", handles)
@@ -103,7 +103,7 @@ func New(file string, cache int, handles int, namespace string) (*LevelDBDatabas
 		return nil, err
 	}
 	// Assemble the wrapper with all the registered metrics
-	ldb := &LevelDBDatabase{
+	ldb := &Database{
 		fn:       file,
 		db:       db,
 		log:      logger,
@@ -124,7 +124,7 @@ func New(file string, cache int, handles int, namespace string) (*LevelDBDatabas
 
 // Close stops the metrics collection, flushes any pending data to disk and closes
 // all io accesses to the underlying key-value store.
-func (db *LevelDBDatabase) Close() error {
+func (db *Database) Close() error {
 	db.quitLock.Lock()
 	defer db.quitLock.Unlock()
 
@@ -140,12 +140,12 @@ func (db *LevelDBDatabase) Close() error {
 }
 
 // Has retrieves if a key is present in the key-value store.
-func (db *LevelDBDatabase) Has(key []byte) (bool, error) {
+func (db *Database) Has(key []byte) (bool, error) {
 	return db.db.Has(key, nil)
 }
 
 // Get retrieves the given key if it's present in the key-value store.
-func (db *LevelDBDatabase) Get(key []byte) ([]byte, error) {
+func (db *Database) Get(key []byte) ([]byte, error) {
 	dat, err := db.db.Get(key, nil)
 	if err != nil {
 		return nil, err
@@ -154,19 +154,19 @@ func (db *LevelDBDatabase) Get(key []byte) ([]byte, error) {
 }
 
 // Put inserts the given value into the key-value store.
-func (db *LevelDBDatabase) Put(key []byte, value []byte) error {
+func (db *Database) Put(key []byte, value []byte) error {
 	return db.db.Put(key, value, nil)
 }
 
 // Delete removes the key from the key-value store.
-func (db *LevelDBDatabase) Delete(key []byte) error {
+func (db *Database) Delete(key []byte) error {
 	return db.db.Delete(key, nil)
 }
 
 // NewBatch creates a write-only key-value store that buffers changes to its host
 // database until a final write is called.
-func (db *LevelDBDatabase) NewBatch() ethdb.Batch {
-	return &levelDBBatch{
+func (db *Database) NewBatch() ethdb.Batch {
+	return &batch{
 		db: db.db,
 		b:  new(leveldb.Batch),
 	}
@@ -174,18 +174,18 @@ func (db *LevelDBDatabase) NewBatch() ethdb.Batch {
 
 // NewIterator creates a binary-alphabetical iterator over the entire keyspace
 // contained within the leveldb database.
-func (db *LevelDBDatabase) NewIterator() ethdb.Iterator {
+func (db *Database) NewIterator() ethdb.Iterator {
 	return db.NewIteratorWithPrefix(nil)
 }
 
 // NewIteratorWithPrefix creates a binary-alphabetical iterator over a subset
 // of database content with a particular key prefix.
-func (db *LevelDBDatabase) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
+func (db *Database) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
 	return db.db.NewIterator(util.BytesPrefix(prefix), nil)
 }
 
 // Stat returns a particular internal stat of the database.
-func (db *LevelDBDatabase) Stat(property string) (string, error) {
+func (db *Database) Stat(property string) (string, error) {
 	return db.db.GetProperty(property)
 }
 
@@ -196,12 +196,12 @@ func (db *LevelDBDatabase) Stat(property string) (string, error) {
 // A nil start is treated as a key before all keys in the data store; a nil limit
 // is treated as a key after all keys in the data store. If both is nil then it
 // will compact entire data store.
-func (db *LevelDBDatabase) Compact(start []byte, limit []byte) error {
+func (db *Database) Compact(start []byte, limit []byte) error {
 	return db.db.CompactRange(util.Range{Start: start, Limit: limit})
 }
 
 // Path returns the path to the database directory.
-func (db *LevelDBDatabase) Path() string {
+func (db *Database) Path() string {
 	return db.fn
 }
 
@@ -222,7 +222,7 @@ func (db *LevelDBDatabase) Path() string {
 //
 // This is how the iostats look like (currently):
 // Read(MB):3895.04860 Write(MB):3654.64712
-func (db *LevelDBDatabase) meter(refresh time.Duration) {
+func (db *Database) meter(refresh time.Duration) {
 	// Create the counters to store current and previous compaction values
 	compactions := make([][]float64, 2)
 	for i := 0; i < 2; i++ {
@@ -326,7 +326,7 @@ func (db *LevelDBDatabase) meter(refresh time.Duration) {
 		// If a warning that db is performing compaction has been displayed, any subsequent
 		// warnings will be withheld for one minute not to overwhelm the user.
 		if paused && delayN-delaystats[0] == 0 && duration.Nanoseconds()-delaystats[1] == 0 &&
-			time.Now().After(lastWritePaused.Add(leveldbDegradationWarnInterval)) {
+			time.Now().After(lastWritePaused.Add(degradationWarnInterval)) {
 			db.log.Warn("Database compacting, degraded performance")
 			lastWritePaused = time.Now()
 		}
@@ -379,40 +379,40 @@ func (db *LevelDBDatabase) meter(refresh time.Duration) {
 	errc <- merr
 }
 
-// levelDBBatch is a write-only leveldb batch that commits changes to its host
-// database when Write is called. A batch cannot be used concurrently.
-type levelDBBatch struct {
+// batch is a write-only leveldb batch that commits changes to its host database
+// when Write is called. A batch cannot be used concurrently.
+type batch struct {
 	db   *leveldb.DB
 	b    *leveldb.Batch
 	size int
 }
 
 // Put inserts the given value into the batch for later committing.
-func (b *levelDBBatch) Put(key, value []byte) error {
+func (b *batch) Put(key, value []byte) error {
 	b.b.Put(key, value)
 	b.size += len(value)
 	return nil
 }
 
 // Delete inserts the a key removal into the batch for later committing.
-func (b *levelDBBatch) Delete(key []byte) error {
+func (b *batch) Delete(key []byte) error {
 	b.b.Delete(key)
-	b.size += 1
+	b.size++
 	return nil
 }
 
 // ValueSize retrieves the amount of data queued up for writing.
-func (b *levelDBBatch) ValueSize() int {
+func (b *batch) ValueSize() int {
 	return b.size
 }
 
 // Write flushes any accumulated data to disk.
-func (b *levelDBBatch) Write() error {
+func (b *batch) Write() error {
 	return b.db.Write(b.b, nil)
 }
 
 // Reset resets the batch for reuse.
-func (b *levelDBBatch) Reset() {
+func (b *batch) Reset() {
 	b.b.Reset()
 	b.size = 0
 }
diff --git a/ethdb/memorydb/memorydb.go b/ethdb/memorydb/memorydb.go
index 9c6bd48be..cc2490ba2 100644
--- a/ethdb/memorydb/memorydb.go
+++ b/ethdb/memorydb/memorydb.go
@@ -37,33 +37,33 @@ var (
 	errMemorydbNotFound = errors.New("not found")
 )
 
-// MemoryDatabase is an ephemeral key-value store. Apart from basic data storage
+// Database is an ephemeral key-value store. Apart from basic data storage
 // functionality it also supports batch writes and iterating over the keyspace in
 // binary-alphabetical order.
-type MemoryDatabase struct {
+type Database struct {
 	db   map[string][]byte
 	lock sync.RWMutex
 }
 
 // New returns a wrapped map with all the required database interface methods
 // implemented.
-func New() *MemoryDatabase {
-	return &MemoryDatabase{
+func New() *Database {
+	return &Database{
 		db: make(map[string][]byte),
 	}
 }
 
 // NewWithCap returns a wrapped map pre-allocated to the provided capcity with
 // all the required database interface methods implemented.
-func NewWithCap(size int) *MemoryDatabase {
-	return &MemoryDatabase{
+func NewWithCap(size int) *Database {
+	return &Database{
 		db: make(map[string][]byte, size),
 	}
 }
 
 // Close deallocates the internal map and ensures any consecutive data access op
 // failes with an error.
-func (db *MemoryDatabase) Close() error {
+func (db *Database) Close() error {
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
@@ -72,7 +72,7 @@ func (db *MemoryDatabase) Close() error {
 }
 
 // Has retrieves if a key is present in the key-value store.
-func (db *MemoryDatabase) Has(key []byte) (bool, error) {
+func (db *Database) Has(key []byte) (bool, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -84,7 +84,7 @@ func (db *MemoryDatabase) Has(key []byte) (bool, error) {
 }
 
 // Get retrieves the given key if it's present in the key-value store.
-func (db *MemoryDatabase) Get(key []byte) ([]byte, error) {
+func (db *Database) Get(key []byte) ([]byte, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -98,7 +98,7 @@ func (db *MemoryDatabase) Get(key []byte) ([]byte, error) {
 }
 
 // Put inserts the given value into the key-value store.
-func (db *MemoryDatabase) Put(key []byte, value []byte) error {
+func (db *Database) Put(key []byte, value []byte) error {
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
@@ -110,7 +110,7 @@ func (db *MemoryDatabase) Put(key []byte, value []byte) error {
 }
 
 // Delete removes the key from the key-value store.
-func (db *MemoryDatabase) Delete(key []byte) error {
+func (db *Database) Delete(key []byte) error {
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
@@ -123,21 +123,21 @@ func (db *MemoryDatabase) Delete(key []byte) error {
 
 // NewBatch creates a write-only key-value store that buffers changes to its host
 // database until a final write is called.
-func (db *MemoryDatabase) NewBatch() ethdb.Batch {
-	return &memoryBatch{
+func (db *Database) NewBatch() ethdb.Batch {
+	return &batch{
 		db: db,
 	}
 }
 
 // NewIterator creates a binary-alphabetical iterator over the entire keyspace
 // contained within the memory database.
-func (db *MemoryDatabase) NewIterator() ethdb.Iterator {
+func (db *Database) NewIterator() ethdb.Iterator {
 	return db.NewIteratorWithPrefix(nil)
 }
 
 // NewIteratorWithPrefix creates a binary-alphabetical iterator over a subset
 // of database content with a particular key prefix.
-func (db *MemoryDatabase) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
+func (db *Database) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -157,19 +157,19 @@ func (db *MemoryDatabase) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
 	for _, key := range keys {
 		values = append(values, db.db[key])
 	}
-	return &memoryIterator{
+	return &iterator{
 		keys:   keys,
 		values: values,
 	}
 }
 
 // Stat returns a particular internal stat of the database.
-func (db *MemoryDatabase) Stat(property string) (string, error) {
+func (db *Database) Stat(property string) (string, error) {
 	return "", errors.New("unknown property")
 }
 
 // Compact is not supported on a memory database.
-func (db *MemoryDatabase) Compact(start []byte, limit []byte) error {
+func (db *Database) Compact(start []byte, limit []byte) error {
 	return errors.New("unsupported operation")
 }
 
@@ -177,7 +177,7 @@ func (db *MemoryDatabase) Compact(start []byte, limit []byte) error {
 //
 // Note, this method is only used for testing (i.e. not public in general) and
 // does not have explicit checks for closed-ness to allow simpler testing code.
-func (db *MemoryDatabase) Len() int {
+func (db *Database) Len() int {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -192,35 +192,35 @@ type keyvalue struct {
 	delete bool
 }
 
-// memoryBatch is a write-only memory batch that commits changes to its host
+// batch is a write-only memory batch that commits changes to its host
 // database when Write is called. A batch cannot be used concurrently.
-type memoryBatch struct {
-	db     *MemoryDatabase
+type batch struct {
+	db     *Database
 	writes []keyvalue
 	size   int
 }
 
 // Put inserts the given value into the batch for later committing.
-func (b *memoryBatch) Put(key, value []byte) error {
+func (b *batch) Put(key, value []byte) error {
 	b.writes = append(b.writes, keyvalue{common.CopyBytes(key), common.CopyBytes(value), false})
 	b.size += len(value)
 	return nil
 }
 
 // Delete inserts the a key removal into the batch for later committing.
-func (b *memoryBatch) Delete(key []byte) error {
+func (b *batch) Delete(key []byte) error {
 	b.writes = append(b.writes, keyvalue{common.CopyBytes(key), nil, true})
 	b.size += 1
 	return nil
 }
 
 // ValueSize retrieves the amount of data queued up for writing.
-func (b *memoryBatch) ValueSize() int {
+func (b *batch) ValueSize() int {
 	return b.size
 }
 
 // Write flushes any accumulated data to the memory database.
-func (b *memoryBatch) Write() error {
+func (b *batch) Write() error {
 	b.db.lock.Lock()
 	defer b.db.lock.Unlock()
 
@@ -235,15 +235,15 @@ func (b *memoryBatch) Write() error {
 }
 
 // Reset resets the batch for reuse.
-func (b *memoryBatch) Reset() {
+func (b *batch) Reset() {
 	b.writes = b.writes[:0]
 	b.size = 0
 }
 
-// memoryIterator can walk over the (potentially partial) keyspace of a memory
-// key value store. Internally it is a deep copy of the entire iterated state,
+// iterator can walk over the (potentially partial) keyspace of a memory key
+// value store. Internally it is a deep copy of the entire iterated state,
 // sorted by keys.
-type memoryIterator struct {
+type iterator struct {
 	inited bool
 	keys   []string
 	values [][]byte
@@ -251,7 +251,7 @@ type memoryIterator struct {
 
 // Next moves the iterator to the next key/value pair. It returns whether the
 // iterator is exhausted.
-func (it *memoryIterator) Next() bool {
+func (it *iterator) Next() bool {
 	// If the iterator was not yet initialized, do it now
 	if !it.inited {
 		it.inited = true
@@ -267,14 +267,14 @@ func (it *memoryIterator) Next() bool {
 
 // Error returns any accumulated error. Exhausting all the key/value pairs
 // is not considered to be an error. A memory iterator cannot encounter errors.
-func (it *memoryIterator) Error() error {
+func (it *iterator) Error() error {
 	return nil
 }
 
 // Key returns the key of the current key/value pair, or nil if done. The caller
 // should not modify the contents of the returned slice, and its contents may
 // change on the next call to Next.
-func (it *memoryIterator) Key() []byte {
+func (it *iterator) Key() []byte {
 	if len(it.keys) > 0 {
 		return []byte(it.keys[0])
 	}
@@ -284,7 +284,7 @@ func (it *memoryIterator) Key() []byte {
 // Value returns the value of the current key/value pair, or nil if done. The
 // caller should not modify the contents of the returned slice, and its contents
 // may change on the next call to Next.
-func (it *memoryIterator) Value() []byte {
+func (it *iterator) Value() []byte {
 	if len(it.values) > 0 {
 		return it.values[0]
 	}
@@ -293,6 +293,6 @@ func (it *memoryIterator) Value() []byte {
 
 // Release releases associated resources. Release should always succeed and can
 // be called multiple times without causing error.
-func (it *memoryIterator) Release() {
+func (it *iterator) Release() {
 	it.keys, it.values = nil, nil
 }
diff --git a/trie/proof_test.go b/trie/proof_test.go
index bcb241bd7..c488f342c 100644
--- a/trie/proof_test.go
+++ b/trie/proof_test.go
@@ -34,17 +34,17 @@ func init() {
 
 // makeProvers creates Merkle trie provers based on different implementations to
 // test all variations.
-func makeProvers(trie *Trie) []func(key []byte) *memorydb.MemoryDatabase {
-	var provers []func(key []byte) *memorydb.MemoryDatabase
+func makeProvers(trie *Trie) []func(key []byte) *memorydb.Database {
+	var provers []func(key []byte) *memorydb.Database
 
 	// Create a direct trie based Merkle prover
-	provers = append(provers, func(key []byte) *memorydb.MemoryDatabase {
+	provers = append(provers, func(key []byte) *memorydb.Database {
 		proof := memorydb.New()
 		trie.Prove(key, 0, proof)
 		return proof
 	})
 	// Create a leaf iterator based Merkle prover
-	provers = append(provers, func(key []byte) *memorydb.MemoryDatabase {
+	provers = append(provers, func(key []byte) *memorydb.Database {
 		proof := memorydb.New()
 		if it := NewIterator(trie.NodeIterator(key)); it.Next() && bytes.Equal(key, it.Key) {
 			for _, p := range it.Prove() {
@@ -180,7 +180,7 @@ func BenchmarkVerifyProof(b *testing.B) {
 	trie, vals := randomTrie(100)
 	root := trie.Hash()
 	var keys []string
-	var proofs []*memorydb.MemoryDatabase
+	var proofs []*memorydb.Database
 	for k := range vals {
 		keys = append(keys, k)
 		proof := memorydb.New()
diff --git a/trie/trie_test.go b/trie/trie_test.go
index cf133706f..1c874370c 100644
--- a/trie/trie_test.go
+++ b/trie/trie_test.go
@@ -542,7 +542,7 @@ func benchGet(b *testing.B, commit bool) {
 	b.StopTimer()
 
 	if commit {
-		ldb := trie.db.diskdb.(*leveldb.LevelDBDatabase)
+		ldb := trie.db.diskdb.(*leveldb.Database)
 		ldb.Close()
 		os.RemoveAll(ldb.Path())
 	}