From 1858583b3b0b9db3794a35fa9689c8c351363dbf Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 22 Dec 2016 17:05:52 -0800
Subject: Clean up after #636

freelist.lenall duplicated freelist.count.
freelist.copyall and mergepgids docs had typos.
---
 freelist.go | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

(limited to 'freelist.go')

diff --git a/freelist.go b/freelist.go
index 53efa8f..e07bf0a 100644
--- a/freelist.go
+++ b/freelist.go
@@ -46,17 +46,8 @@ func (f *freelist) pending_count() int {
 	return count
 }
 
-// lenall returns the combined number of all free ids and all pending ids.
-func (f *freelist) lenall() int {
-	n := len(f.ids)
-	for _, list := range f.pending {
-		n += len(list)
-	}
-	return n
-}
-
-// all copies into dst a list of all free ids and all pending ids in one sorted list.
-// f.lenall returns the minimum length required for dst.
+// copyall copies into dst a list of all free ids and all pending ids in one sorted list.
+// f.count returns the minimum length required for dst.
 func (f *freelist) copyall(dst []pgid) {
 	m := make(pgids, 0, len(f.pending)) // len(f.pending) undercounts, but it is a start
 	for _, list := range f.pending {
@@ -200,7 +191,7 @@ func (f *freelist) write(p *page) error {
 
 	// The page.count can only hold up to 64k elements so if we overflow that
 	// number then we handle it by putting the size in the first element.
-	lenids := f.lenall()
+	lenids := f.count()
 	if lenids == 0 {
 		p.count = uint16(lenids)
 	} else if lenids < 0xFFFF {
-- 
cgit v1.2.3


From 0e120dc4700273c23d10ef64f25663fa21b84e9b Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 22 Dec 2016 17:20:50 -0800
Subject: Precalculate size of pending pgids in freelist.copyall

This recovers the slight alloc regression in #636.
---
 freelist.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'freelist.go')

diff --git a/freelist.go b/freelist.go
index e07bf0a..de59aaa 100644
--- a/freelist.go
+++ b/freelist.go
@@ -49,7 +49,7 @@ func (f *freelist) pending_count() int {
 // copyall copies into dst a list of all free ids and all pending ids in one sorted list.
 // f.count returns the minimum length required for dst.
 func (f *freelist) copyall(dst []pgid) {
-	m := make(pgids, 0, len(f.pending)) // len(f.pending) undercounts, but it is a start
+	m := make(pgids, 0, f.pending_count())
 	for _, list := range f.pending {
 		m = append(m, list...)
 	}
-- 
cgit v1.2.3


From 7adfa44e02041a6d9b571025a8237a13fa6fbde8 Mon Sep 17 00:00:00 2001
From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 22 Dec 2016 17:22:44 -0800
Subject: Fix freelist.size calculation for large freelists

freelist.size did not account for the extra
fake freelist item used to hold the number of
elements when the freelist is large.
---
 freelist.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'freelist.go')

diff --git a/freelist.go b/freelist.go
index de59aaa..aba48f5 100644
--- a/freelist.go
+++ b/freelist.go
@@ -24,7 +24,12 @@ func newFreelist() *freelist {
 
 // size returns the size of the page after serialization.
 func (f *freelist) size() int {
-	return pageHeaderSize + (int(unsafe.Sizeof(pgid(0))) * f.count())
+	n := f.count()
+	if n >= 0xFFFF {
+		// The first element will be used to store the count. See freelist.write.
+		n++
+	}
+	return pageHeaderSize + (int(unsafe.Sizeof(pgid(0))) * n)
 }
 
 // count returns count of pages on the freelist
-- 
cgit v1.2.3