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Diffstat (limited to 'page.go')
-rw-r--r--page.go85
1 files changed, 73 insertions, 12 deletions
diff --git a/page.go b/page.go
index c18c6b4..d05dce6 100644
--- a/page.go
+++ b/page.go
@@ -1,6 +1,8 @@
package bolt
import (
+ "fmt"
+ "os"
"unsafe"
)
@@ -10,6 +12,9 @@ const maxAllocSize = 0xFFFFFFF
const minKeysPerPage = 2
const maxNodesPerPage = 65535
+const branchPageElementSize = int(unsafe.Sizeof(branchPageElement{}))
+const leafPageElementSize = int(unsafe.Sizeof(leafPageElement{}))
+
const (
p_branch = 0x01
p_leaf = 0x02
@@ -28,29 +33,46 @@ type page struct {
ptr uintptr
}
+// typ returns a human readable page type string used for debugging.
+func (p *page) typ() string {
+ if (p.flags & p_branch) != 0 {
+ return "branch"
+ } else if (p.flags & p_leaf) != 0 {
+ return "leaf"
+ } else if (p.flags & p_meta) != 0 {
+ return "meta"
+ } else if (p.flags & p_sys) != 0 {
+ return "system"
+ } else if (p.flags & p_freelist) != 0 {
+ return "freelist"
+ }
+ return fmt.Sprintf("unknown<%02x>", p.flags)
+}
+
// meta returns a pointer to the metadata section of the page.
func (p *page) meta() *meta {
return (*meta)(unsafe.Pointer(&p.ptr))
}
-// lnode retrieves the leaf node by index
-func (p *page) lnode(index int) *lnode {
- return &((*[maxNodesPerPage]lnode)(unsafe.Pointer(&p.ptr)))[index]
+// leafPageElement retrieves the leaf node by index
+func (p *page) leafPageElement(index uint16) *leafPageElement {
+ n := &((*[maxNodesPerPage]leafPageElement)(unsafe.Pointer(&p.ptr)))[index]
+ return n
}
-// lnodes retrieves a list of leaf nodes.
-func (p *page) lnodes() []lnode {
- return ((*[maxNodesPerPage]lnode)(unsafe.Pointer(&p.ptr)))[:]
+// leafPageElements retrieves a list of leaf nodes.
+func (p *page) leafPageElements() []leafPageElement {
+ return ((*[maxNodesPerPage]leafPageElement)(unsafe.Pointer(&p.ptr)))[:]
}
-// bnode retrieves the branch node by index
-func (p *page) bnode(index int) *bnode {
- return &((*[maxNodesPerPage]bnode)(unsafe.Pointer(&p.ptr)))[index]
+// branchPageElement retrieves the branch node by index
+func (p *page) branchPageElement(index uint16) *branchPageElement {
+ return &((*[maxNodesPerPage]branchPageElement)(unsafe.Pointer(&p.ptr)))[index]
}
-// bnodes retrieves a list of branch nodes.
-func (p *page) bnodes() []bnode {
- return ((*[maxNodesPerPage]bnode)(unsafe.Pointer(&p.ptr)))[:]
+// branchPageElements retrieves a list of branch nodes.
+func (p *page) branchPageElements() []branchPageElement {
+ return ((*[maxNodesPerPage]branchPageElement)(unsafe.Pointer(&p.ptr)))[:]
}
// freelist retrieves a list of page ids from a freelist page.
@@ -58,8 +80,47 @@ func (p *page) freelist() []pgid {
return ((*[maxNodesPerPage]pgid)(unsafe.Pointer(&p.ptr)))[0:p.count]
}
+// dump writes n bytes of the page to STDERR as hex output.
+func (p *page) hexdump(n int) {
+ buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:n]
+ fmt.Fprintf(os.Stderr, "%x\n", buf)
+}
+
type pages []*page
func (s pages) Len() int { return len(s) }
func (s pages) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s pages) Less(i, j int) bool { return s[i].id < s[j].id }
+
+// branchPageElement represents a node on a branch page.
+type branchPageElement struct {
+ pos uint32
+ ksize uint32
+ pgid pgid
+}
+
+// key returns a byte slice of the node key.
+func (n *branchPageElement) key() []byte {
+ buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+ return buf[n.pos : n.pos+n.ksize]
+}
+
+// leafPageElement represents a node on a leaf page.
+type leafPageElement struct {
+ flags uint32
+ pos uint32
+ ksize uint32
+ vsize uint32
+}
+
+// key returns a byte slice of the node key.
+func (n *leafPageElement) key() []byte {
+ buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+ return buf[n.pos : n.pos+n.ksize]
+}
+
+// value returns a byte slice of the node value.
+func (n *leafPageElement) value() []byte {
+ buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+ return buf[n.pos+n.ksize : n.pos+n.ksize+n.vsize]
+}