Intermediate commit.

README.md

@@ -1,4 +1,38 @@
 bolt
 ====
 
+## Overview
+
 A low-level key/value database for Go.
+
+
+## API
+
+### DB
+
+### Creating a database
+
+```
+db := DB()
+err := db.Open("/path/to/db", 0666)
+...
+err := db.Close()
+```
+
+### Creating a bucket
+
+
+* Cursor
+
+
+```
+DB
+Bucket
+Transaction / RWTransaction
+Cursor / RWCursor
+
+page
+meta
+branchNode
+leafNode
+```

branch_node.go

@@ -10,86 +10,7 @@ const (
 	dupNode = 0x04
 )
 
-// branchNode represents a node on a branch page.
-type branchNode struct {
-	pgno    uint32
-	flags   uint16
-	keySize uint16
-	data    uintptr // Pointer to the beginning of the data.
-}
-
 // key returns a byte slice that of the key data.
 func (n *branchNode) key() []byte {
 	return (*[MaxKeySize]byte)(unsafe.Pointer(&n.data))[:n.keySize]
 }
-
-func (n *branchNode) size() int {
-	return 0 // TODO: offsetof(MDB_node, mn_data)
-}
-
-// TODO: #define INDXSIZE(k)	 (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
-// TODO: #define LEAFSIZE(k, d)	 (NODESIZE + (k)->mv_size + (d)->mv_size)
-// TODO: #define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
-// TODO: #define NODEKEY(node)	 (void *)((node)->mn_data)
-// TODO: #define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)
-// TODO: #define NODEPGNO(node)  ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
-// TODO: #define SETPGNO(node,pgno)	do { (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
-// TODO: #define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
-// TODO: #define SETDSZ(node,size)	do { (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
-// TODO: #define NODEKSZ(node)	 ((node)->mn_ksize)
-
-// TODO: #define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
-
-// TODO: #define MDB_GET_KEY(node, keyptr)	{ if ((keyptr) != NULL) { (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
-// TODO: #define MDB_GET_KEY2(node, key)	{ key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
-
-// Compact the main page after deleting a node on a subpage.
-// @param[in] mp The main page to operate on.
-// @param[in] indx The index of the subpage on the main page.
-func (n *node) shrink(index int) {
-	/*
-		MDB_node *node;
-		MDB_page *sp, *xp;
-		char *base;
-		int nsize, delta;
-		indx_t		 i, numkeys, ptr;
-
-		node = NODEPTR(mp, indx);
-		sp = (MDB_page *)NODEDATA(node);
-		delta = SIZELEFT(sp);
-		xp = (MDB_page *)((char *)sp + delta);
-
-		// shift subpage upward
-		if (IS_LEAF2(sp)) {
-			nsize = NUMKEYS(sp) * sp->mp_pad;
-			if (nsize & 1)
-				return;		// do not make the node uneven-sized
-			memmove(METADATA(xp), METADATA(sp), nsize);
-		} else {
-			int i;
-			numkeys = NUMKEYS(sp);
-			for (i=numkeys-1; i>=0; i--)
-				xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
-		}
-		xp->mp_upper = sp->mp_lower;
-		xp->mp_lower = sp->mp_lower;
-		xp->mp_flags = sp->mp_flags;
-		xp->mp_pad = sp->mp_pad;
-		COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
-
-		nsize = NODEDSZ(node) - delta;
-		SETDSZ(node, nsize);
-
-		// shift lower nodes upward
-		ptr = mp->mp_ptrs[indx];
-		numkeys = NUMKEYS(mp);
-		for (i = 0; i < numkeys; i++) {
-			if (mp->mp_ptrs[i] <= ptr)
-				mp->mp_ptrs[i] += delta;
-		}
-
-		base = (char *)mp + mp->mp_upper;
-		memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
-		mp->mp_upper += delta;
-	*/
-}

bucket.go

@@ -29,4 +29,3 @@ type bucket struct {
 	entries   uint64
 	root      pgno
 }
-

cursor.go

@@ -5,31 +5,19 @@ package bolt
 const (
 	c_initialized = 0x01 /**< cursor has been initialized and is valid */
 	c_eof         = 0x02 /**< No more data */
-	c_sub         = 0x04 /**< Cursor is a sub-cursor */
 	c_del         = 0x08 /**< last op was a cursor_del */
 	c_splitting   = 0x20 /**< Cursor is in page_split */
 	c_untrack     = 0x40 /**< Un-track cursor when closing */
 )
 
-// TODO: #define MDB_NOSPILL	0x8000 /** Do not spill pages to disk if txn is getting full, may fail instead */
-
 /*
 type Cursor interface {
 	First() error
-	FirstDup() error
+	Last() error
-	Get() ([]byte, []byte, error)
-	GetRange() ([]byte, []byte, error)
-	Current() ([]byte, []byte, error)
-	Last()
-	LastDup()
 	Next() ([]byte, []byte, error)
-	NextDup() ([]byte, []byte, error)
-	NextNoDup() ([]byte, []byte, error)
 	Prev() ([]byte, []byte, error)
-	PrevDup() ([]byte, []byte, error)
+	Current() ([]byte, []byte, error)
-	PrevNoDup() ([]byte, []byte, error)
+	Get([]byte) ([]byte, error)
-	Set() ([]byte, []byte, error)
-	SetRange() ([]byte, []byte, error)
 }
 */
 
@@ -37,10 +25,8 @@ type Cursor struct {
 	flags       int
 	next        *Cursor
 	backup      *Cursor
-	subcursor   *Cursor
 	transaction *Transaction
 	bucket      *Bucket
-	subbucket   *Bucket
 	top         int
 	pages       []*page
 	indices     []int /* the index of the node for the page at the same level */
@@ -53,12 +39,6 @@ func (c *Cursor) Get(key []byte) ([]byte, error) {
 			int		 exact = 0;
 			int		 (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
 
-			if (mc == NULL)
-				return EINVAL;
-
-			if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
-				return MDB_BAD_TXN;
-
 			switch (op) {
 			case MDB_GET_CURRENT:
 				if (!(mc->mc_flags & C_INITIALIZED)) {
@@ -222,14 +202,14 @@ func (c *Cursor) page(key []byte, flags int) (*page, error) {
 		if (flags & ps_first) != 0 {
 			index = 0
 		} else if (flags & ps_last) != 0 {
-			index = indx(p.numkeys()) - 1;
+			index = indx(p.numkeys()) - 1
 		} else {
-			node, i, exact := p.find(key, c.transaction.db.pageSize);
+			node, i, exact := p.find(key, c.transaction.db.pageSize)
 			if exact {
 				c.indices[c.top] = i
 			}
 			if node == nil {
-				index = indx(p.numkeys()) - 1;
+				index = indx(p.numkeys()) - 1
 			} else {
 				index = indx(c.indices[c.top])
 				if !exact {
@@ -279,8 +259,8 @@ func (c *Cursor) push(p *page) {
 	c.top = len(c.pages) - 1
 }
 
-// page retrieves the last page on the page stack.
+// currentPage retrieves the last page on the page stack.
-func (c *Cursor) page() *page {
+func (c *Cursor) currentPage() *page {
 	top := len(c.pages)
 	if top > 0 {
 		return c.pages[top]
@@ -306,7 +286,6 @@ func (c *Cursor) currentLeafNode() *node {
 	return nil
 }
 
-
 //                                                                            //
 //                                                                            //
 //                                                                            //
@@ -642,9 +621,6 @@ func (c *Cursor) page_touch() int {
 	return 0
 }
 
-
-
-
 // Search for the lowest key under the current branch page.
 // This just bypasses a NUMKEYS check in the current page
 // before calling mdb_page_search_root(), because the callers

node.go

@@ -4,14 +4,26 @@ import (
 	"unsafe"
 )
 
-// leafNode represents a node on a leaf page.
+// node represents a node on a page.
-type leafNode struct {
+type node struct {
 	flags   uint16
 	keySize uint16
+}
+
+// leafNode represents a node on a leaf page.
+type leafNode struct {
+	node
 	dataSize uint32
 	data     uintptr // Pointer to the beginning of the data.
 }
 
+// branchNode represents a node on a branch page.
+type branchNode struct {
+	node
+	pgno uint32
+	data uintptr // Pointer to the beginning of the data.
+}
+
 // key returns a byte slice that of the key data.
 func (n *leafNode) key() []byte {
 	return (*[MaxKeySize]byte)(unsafe.Pointer(&n.data))[:n.keySize]

page.go

@@ -21,7 +21,6 @@ const (
 	p_overflow = 0x04
 	p_meta     = 0x08
 	p_dirty    = 0x10   /**< dirty page, also set for #P_SUBP pages */
-	p_sub      = 0x40
 	p_keep     = 0x8000 /**< leave this page alone during spill */
 
 	p_invalid = ^pgno(0)
@@ -124,13 +123,13 @@ func (p *page) find(key []byte, pageSize int) (*node, int, bool) {
 
 	// Perform a binary search to find the correct node.
 	var i, rc int
-	for ; low <= high; {
+	for low <= high {
 		i = (low + high) / 2
 
 		node = p.node(indx(i))
 		rc = bytes.Compare(key, node.key())
 		if rc == 0 {
-			break;
+			break
 		} else if rc > 0 {
 			low = i + 1
 		} else {

rwcursor.go

@@ -1,5 +1,12 @@
 package bolt
 
+/*
+type RWCursor interface {
+	Put([]byte, []byte) (error)
+	Delete([]byte) (error)
+}
+*/
+
 // RWCursor represents a cursor that can read and write data for a bucket.
 type RWCursor struct {
 	Cursor

rwtransaction.go

@@ -4,6 +4,4 @@ package bolt
 // Only one read/write transaction can be active for a DB at a time.
 type RWTransaction struct {
 	Transaction
-	pagestate  pagestate
 }
-