Merge branch 'master' of https://github.com/boltdb/bolt into fix-deletion

Conflicts:
	node.go

7 files changed, 79 insertions, 5 deletions

diff --git a/bucket.go b/bucket.go
index 37dba0f..43204f7 100644
--- a/bucket.go
+++ b/bucket.go
@@ -476,6 +476,7 @@ func (b *Bucket) spill() error {
 	b.rootNode = b.rootNode.root()
 
 	// Update the root node for this bucket.
+	_assert(b.rootNode.pgid < b.tx.meta.pgid, "pgid (%d) above high water mark (%d)", b.rootNode.pgid, b.tx.meta.pgid)
 	b.root = b.rootNode.pgid
 
 	return nil
diff --git a/cmd/bolt/info.go b/cmd/bolt/info.go
new file mode 100644
index 0000000..1e9e0d8
--- /dev/null
+++ b/cmd/bolt/info.go
@@ -0,0 +1,26 @@
+package main
+
+import (
+	"os"
+
+	"github.com/boltdb/bolt"
+)
+
+// Info prints basic information about a database.
+func Info(path string) {
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		fatal(err)
+		return
+	}
+
+	db, err := bolt.Open(path, 0600)
+	if err != nil {
+		fatal(err)
+		return
+	}
+	defer db.Close()
+
+	// Print basic database info.
+	var info = db.Info()
+	printf("Page Size: %d", info.PageSize)
+}
diff --git a/cmd/bolt/info_test.go b/cmd/bolt/info_test.go
new file mode 100644
index 0000000..668cc61
--- /dev/null
+++ b/cmd/bolt/info_test.go
@@ -0,0 +1,32 @@
+package main_test
+
+import (
+	"testing"
+
+	"github.com/boltdb/bolt"
+	. "github.com/boltdb/bolt/cmd/bolt"
+	"github.com/stretchr/testify/assert"
+)
+
+// Ensure that a database info can be printed.
+func TestInfo(t *testing.T) {
+	SetTestMode(true)
+	open(func(db *bolt.DB, path string) {
+		db.Update(func(tx *bolt.Tx) error {
+			tx.CreateBucket([]byte("widgets"))
+			b := tx.Bucket([]byte("widgets"))
+			b.Put([]byte("foo"), []byte("0000"))
+			return nil
+		})
+		db.Close()
+		output := run("info", path)
+		assert.Equal(t, `Page Size: 4096`, output)
+	})
+}
+
+// Ensure that an error is reported if the database is not found.
+func TestInfo_NotFound(t *testing.T) {
+	SetTestMode(true)
+	output := run("info", "no/such/db")
+	assert.Equal(t, "stat no/such/db: no such file or directory", output)
+}
diff --git a/cmd/bolt/main.go b/cmd/bolt/main.go
index 1af2636..3397042 100644
--- a/cmd/bolt/main.go
+++ b/cmd/bolt/main.go
@@ -26,6 +26,14 @@ func NewApp() *cli.App {
 	app.Version = fmt.Sprintf("0.1.0 (%s %s)", branch, commit)
 	app.Commands = []cli.Command{
 		{
+			Name:  "info",
+			Usage: "Print basic information about a database",
+			Action: func(c *cli.Context) {
+				path := c.Args().Get(0)
+				Info(path)
+			},
+		},
+		{
 			Name:  "get",
 			Usage: "Retrieve a value for given key in a bucket",
 			Action: func(c *cli.Context) {
diff --git a/db.go b/db.go
index d96a161..0b74621 100644
--- a/db.go
+++ b/db.go
@@ -705,6 +705,10 @@ func (m *meta) copy(dest *meta) {
 
 // write writes the meta onto a page.
 func (m *meta) write(p *page) {
+
+	_assert(m.root.root < m.pgid, "root bucket pgid (%d) above high water mark (%d)", m.root.root, m.pgid)
+	_assert(m.freelist < m.pgid, "freelist pgid (%d) above high water mark (%d)", m.freelist, m.pgid)
+
 	// Page id is either going to be 0 or 1 which we can determine by the transaction ID.
 	p.id = pgid(m.txid % 2)
 	p.flags |= metaPageFlag
diff --git a/node.go b/node.go
index d9ab1ad..5ad581e 100644
--- a/node.go
+++ b/node.go
@@ -96,6 +96,7 @@ func (n *node) prevSibling() *node {
 
 // put inserts a key/value.
 func (n *node) put(oldKey, newKey, value []byte, pgid pgid, flags uint32) {
+	_assert(pgid < n.bucket.tx.meta.pgid, "pgid (%d) above high water mark (%d)", pgid, n.bucket.tx.meta.pgid)
 	_assert(len(oldKey) > 0, "put: zero-length old key")
 	_assert(len(newKey) > 0, "put: zero-length new key")
 
@@ -284,6 +285,7 @@ func (n *node) spill() error {
 		}
 
 		// Write the node.
+		_assert(p.id < tx.meta.pgid, "pgid (%d) above high water mark (%d)", p.id, tx.meta.pgid)
 		node.pgid = p.id
 		node.write(p)
 
@@ -314,6 +316,7 @@ func (n *node) spill() error {
 		}
 
 		// Write the new root.
+		_assert(p.id < tx.meta.pgid, "pgid (%d) above high water mark (%d)", p.id, tx.meta.pgid)
 		parent.pgid = p.id
 		parent.write(p)
 	}
diff --git a/node_test.go b/node_test.go
index f639376..1393e2a 100644
--- a/node_test.go
+++ b/node_test.go
@@ -9,7 +9,7 @@ import (
 
 // Ensure that a node can insert a key/value.
 func TestNode_put(t *testing.T) {
-	n := &node{inodes: make(inodes, 0)}
+	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{meta: &meta{pgid: 1}}}}
 	n.put([]byte("baz"), []byte("baz"), []byte("2"), 0, 0)
 	n.put([]byte("foo"), []byte("foo"), []byte("0"), 0, 0)
 	n.put([]byte("bar"), []byte("bar"), []byte("1"), 0, 0)
@@ -58,7 +58,7 @@ func TestNode_read_LeafPage(t *testing.T) {
 // Ensure that a node can serialize into a leaf page.
 func TestNode_write_LeafPage(t *testing.T) {
 	// Create a node.
-	n := &node{isLeaf: true, inodes: make(inodes, 0)}
+	n := &node{isLeaf: true, inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{meta: &meta{pgid: 1}}}}
 	n.put([]byte("susy"), []byte("susy"), []byte("que"), 0, 0)
 	n.put([]byte("ricki"), []byte("ricki"), []byte("lake"), 0, 0)
 	n.put([]byte("john"), []byte("john"), []byte("johnson"), 0, 0)
@@ -85,7 +85,7 @@ func TestNode_write_LeafPage(t *testing.T) {
 // Ensure that a node can split into appropriate subgroups.
 func TestNode_split(t *testing.T) {
 	// Create a node.
-	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{}}}
+	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{meta: &meta{pgid: 1}}}}
 	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
 	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
 	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0, 0)
@@ -104,7 +104,7 @@ func TestNode_split(t *testing.T) {
 // Ensure that a page with the minimum number of inodes just returns a single node.
 func TestNode_split_MinKeys(t *testing.T) {
 	// Create a node.
-	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{}}}
+	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{meta: &meta{pgid: 1}}}}
 	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
 	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
 
@@ -116,7 +116,7 @@ func TestNode_split_MinKeys(t *testing.T) {
 // Ensure that a node that has keys that all fit on a page just returns one leaf.
 func TestNode_split_SinglePage(t *testing.T) {
 	// Create a node.
-	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{}}}
+	n := &node{inodes: make(inodes, 0), bucket: &Bucket{tx: &Tx{meta: &meta{pgid: 1}}}}
 	n.put([]byte("00000001"), []byte("00000001"), []byte("0123456701234567"), 0, 0)
 	n.put([]byte("00000002"), []byte("00000002"), []byte("0123456701234567"), 0, 0)
 	n.put([]byte("00000003"), []byte("00000003"), []byte("0123456701234567"), 0, 0)