Merge pull request #6 from vulcanize/statedb

Add go report card and some additional detail/comments

README.md

@@ -1,5 +1,6 @@
 ## pg-ipfs-ethdb
 
+[![Go Report Card](https://goreportcard.com/badge/github.com/vulcanize/pg-ipfs-ethdb)](https://goreportcard.com/report/github.com/vulcanize/pg-ipfs-ethdb)
 
 > go-ethereum ethdb interfaces for Ethereum state data stored in Postgres-backed IPFS
 
@@ -29,6 +30,8 @@ with a few exceptions:
 package main
 
 import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/trie"
 	"github.com/jmoiron/sqlx"
 	"github.com/vulcanize/pg-ipfs-ethdb"
@@ -40,8 +43,12 @@ func main() {
 
     kvs := ipfsethdb.NewKeyValueStore(db)
     trieDB := trie.NewDatabase(kvs)
+    t, _ := trie.New(common.Hash{}, trieDB)
+    // do stuff with trie or trieDB
 
-    // do stuff
+    database := ipfsethdb.NewDatabase(db)
+    stateDatabase := state.NewDatabase(database)
+    // do stuff with the state database
 }
 ```
 
@@ -50,6 +57,43 @@ EXCEPTIONS: AncientReader, AncientWriter, and Iteratee interfaces are not functi
 Ancient data does not currently have a representation on IPFS, and recapitulation of the database key iterator is complicated since go-ethereum
 types that use this interface expect the iterator to iterate over keccak256 hash keys, whereas the keys for Ethereum data on IPFS are derived from that hash but not the hash itself.
 
+Iteratee interface is only used in Geth for various tests, in trie/sync_bloom.go (for fast sync), and for rawdb.InspectDatabase while the Ancient interfaces are only used for Ancient data operations,
+so we don't need these interfaces for the majority of state operations.
+
+The ethdb.Iteratee/ethdb.Iterator interfaces should not be confused with the trie.NodeIterator or state.NodeIterator.
+These can be constructed from the ethdb.KeyValueStore and ethdb.Database interfaces, respectively:
+
+```go
+package main
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/state/snapshot"
+	"github.com/ethereum/go-ethereum/trie"
+	"github.com/jmoiron/sqlx"
+	"github.com/vulcanize/pg-ipfs-ethdb"
+)
+
+func main() {
+    connectStr := "postgresql://localhost:5432/vulcanize_testing?sslmode=disable"
+    db, _ := sqlx.Connect("postgres", connectStr)
+
+    kvs := ipfsethdb.NewKeyValueStore(db)
+    trieDB := trie.NewDatabase(kvs)
+    t, _ := trie.New(common.Hash{}, trieDB)
+    trieNodeIterator := t.NodeIterator([]byte{})
+    // do stuff with trie node iterator
+
+    database := ipfsethdb.NewDatabase(db)
+    stateDatabase := state.NewDatabase(database)
+    snapshotTree := snapshot.New(kvs, trieDB, 1, common.Hash{}, false)
+    stateDB, _ := state.New(common.Hash{}, stateDatabase, snapshotTree)
+    stateDBNodeIterator := state.NewNodeIterator(stateDB)
+    // do stuff with the statedb node iterator
+}
+```
+
 ## Maintainers
 @vulcanize
 @AFDudley

batch.go

@@ -21,12 +21,14 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
+// Batch is the type that satisfies the ethdb.Batch interface for PG-IPFS Ethereum data
 type Batch struct {
 	db   *sqlx.DB
 	tx   *sqlx.Tx
 	size int
 }
 
+// NewBatch returns a ethdb.Batch interface for PG-IPFS
 func NewBatch(db *sqlx.DB) ethdb.Batch {
 	return &Batch{
 		db: db,

database.go

@@ -35,16 +35,19 @@ var (
 	dbSizePgStr = "SELECT pg_database_size(current_database())"
 )
 
+// Database is the type that satisfies the ethdb.Database and ethdb.KeyValueStore interfaces for PG-IPFS Ethereum data
 type Database struct {
 	db *sqlx.DB
 }
 
+// NewKeyValueStore returns a ethdb.KeyValueStore interface for PG-IPFS
 func NewKeyValueStore(db *sqlx.DB) ethdb.KeyValueStore {
 	return &Database{
 		db: db,
 	}
 }
 
+// NewDatabase returns a ethdb.Database interface for PG-IPFS
 func NewDatabase(db *sqlx.DB) ethdb.Database {
 	return &Database{
 		db: db,
@@ -190,7 +193,7 @@ func (d *Database) NewBatch() ethdb.Batch {
 // Note: This method assumes that the prefix is NOT part of the start, so there's
 // no need for the caller to prepend the prefix to the start
 func (d *Database) NewIterator(prefix []byte, start []byte) ethdb.Iterator {
-	return NewIterator([]byte{}, []byte{}, d.db)
+	return NewIterator(start, prefix, d.db)
 }
 
 // Close satisfies the io.Closer interface

iterator.go

@@ -21,14 +21,18 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
-// We don't need these iterator interfaces right now
+// Iterator is the type that satisfies the ethdb.Iterator interface for PG-IPFS Ethereum data
 // Iteratee interface is only used in Geth for various tests, trie/sync_bloom.go (for fast sync), and rawdb.InspectDatabase
+// Don't need this interface for the majority of state operations
+// This should not be confused with trie.NodeIterator or state.NodeIteraor (which can be constructed from the ethdb.KeyValueStore and ethdb.Database interfaces)
+// ethdb.KeyValueStore => trie.Database => trie.Trie => trie.NodeIterator
 type Iterator struct {
 	db                 *sqlx.DB
 	currentKey, prefix []byte
 	err                error
 }
 
+// NewIterator returns a ethdb.Iterator interface for PG-IPFS
 func NewIterator(start, prefix []byte, db *sqlx.DB) ethdb.Iterator {
 	return &Iterator{
 		db:         db,