diff options
Diffstat (limited to 'vendor/github.com/boltdb/bolt/page.go')
-rw-r--r-- | vendor/github.com/boltdb/bolt/page.go | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/vendor/github.com/boltdb/bolt/page.go b/vendor/github.com/boltdb/bolt/page.go deleted file mode 100644 index cde403ae8..000000000 --- a/vendor/github.com/boltdb/bolt/page.go +++ /dev/null @@ -1,197 +0,0 @@ -package bolt - -import ( - "fmt" - "os" - "sort" - "unsafe" -) - -const pageHeaderSize = int(unsafe.Offsetof(((*page)(nil)).ptr)) - -const minKeysPerPage = 2 - -const branchPageElementSize = int(unsafe.Sizeof(branchPageElement{})) -const leafPageElementSize = int(unsafe.Sizeof(leafPageElement{})) - -const ( - branchPageFlag = 0x01 - leafPageFlag = 0x02 - metaPageFlag = 0x04 - freelistPageFlag = 0x10 -) - -const ( - bucketLeafFlag = 0x01 -) - -type pgid uint64 - -type page struct { - id pgid - flags uint16 - count uint16 - overflow uint32 - ptr uintptr -} - -// typ returns a human readable page type string used for debugging. -func (p *page) typ() string { - if (p.flags & branchPageFlag) != 0 { - return "branch" - } else if (p.flags & leafPageFlag) != 0 { - return "leaf" - } else if (p.flags & metaPageFlag) != 0 { - return "meta" - } else if (p.flags & freelistPageFlag) != 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)) -} - -// leafPageElement retrieves the leaf node by index -func (p *page) leafPageElement(index uint16) *leafPageElement { - n := &((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[index] - return n -} - -// leafPageElements retrieves a list of leaf nodes. -func (p *page) leafPageElements() []leafPageElement { - if p.count == 0 { - return nil - } - return ((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[:] -} - -// branchPageElement retrieves the branch node by index -func (p *page) branchPageElement(index uint16) *branchPageElement { - return &((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[index] -} - -// branchPageElements retrieves a list of branch nodes. -func (p *page) branchPageElements() []branchPageElement { - if p.count == 0 { - return nil - } - return ((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[:] -} - -// 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 (*[maxAllocSize]byte)(unsafe.Pointer(&buf[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 (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize:n.ksize] -} - -// value returns a byte slice of the node value. -func (n *leafPageElement) value() []byte { - buf := (*[maxAllocSize]byte)(unsafe.Pointer(n)) - return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize:n.vsize] -} - -// PageInfo represents human readable information about a page. -type PageInfo struct { - ID int - Type string - Count int - OverflowCount int -} - -type pgids []pgid - -func (s pgids) Len() int { return len(s) } -func (s pgids) Swap(i, j int) { s[i], s[j] = s[j], s[i] } -func (s pgids) Less(i, j int) bool { return s[i] < s[j] } - -// merge returns the sorted union of a and b. -func (a pgids) merge(b pgids) pgids { - // Return the opposite slice if one is nil. - if len(a) == 0 { - return b - } - if len(b) == 0 { - return a - } - merged := make(pgids, len(a)+len(b)) - mergepgids(merged, a, b) - return merged -} - -// mergepgids copies the sorted union of a and b into dst. -// If dst is too small, it panics. -func mergepgids(dst, a, b pgids) { - if len(dst) < len(a)+len(b) { - panic(fmt.Errorf("mergepgids bad len %d < %d + %d", len(dst), len(a), len(b))) - } - // Copy in the opposite slice if one is nil. - if len(a) == 0 { - copy(dst, b) - return - } - if len(b) == 0 { - copy(dst, a) - return - } - - // Merged will hold all elements from both lists. - merged := dst[:0] - - // Assign lead to the slice with a lower starting value, follow to the higher value. - lead, follow := a, b - if b[0] < a[0] { - lead, follow = b, a - } - - // Continue while there are elements in the lead. - for len(lead) > 0 { - // Merge largest prefix of lead that is ahead of follow[0]. - n := sort.Search(len(lead), func(i int) bool { return lead[i] > follow[0] }) - merged = append(merged, lead[:n]...) - if n >= len(lead) { - break - } - - // Swap lead and follow. - lead, follow = follow, lead[n:] - } - - // Append what's left in follow. - _ = append(merged, follow...) -} |