Fix bugs

Author: Yuan Ting

.idea/.gitignore

@@ -0,0 +1,107 @@
+From e1ffca3629c16a5a19eebe8f7805176ce69cbf97 Mon Sep 17 00:00:00 2001
+From: Alexander Morozov <lk4d4@docker.com>
+Date: Thu, 28 Jan 2016 09:51:40 -0800
+Subject: [PATCH] Use sync.Pool for small pages in db.allocate
+
+Benchmark results:
+benchmark                          old ns/op     new ns/op     delta
+BenchmarkDBBatchAutomatic-4        2552625       2485200       -2.64%
+BenchmarkDBBatchSingle-4           59632698      50757603      -14.88%
+BenchmarkDBBatchManual10x100-4     2564789       2452735       -4.37%
+
+benchmark                          old allocs     new allocs     delta
+BenchmarkDBBatchAutomatic-4        10199          10202          +0.03%
+BenchmarkDBBatchSingle-4           56642          56653          +0.02%
+BenchmarkDBBatchManual10x100-4     5986           5995           +0.15%
+
+benchmark                          old bytes     new bytes     delta
+BenchmarkDBBatchAutomatic-4        433587        382462        -11.79%
+BenchmarkDBBatchSingle-4           32504533      16308931      -49.83%
+BenchmarkDBBatchManual10x100-4     1362370       881765        -35.28%
+
+Signed-off-by: Alexander Morozov <lk4d4@docker.com>
+---
+ db.go | 18 ++++++++++++++++--
+ tx.go | 16 ++++++++++++++--
+ 2 files changed, 30 insertions(+), 4 deletions(-)
+
+diff --git a/db.go b/db.go
+index 0f1e1bc3..5d487092 100644
+--- a/db.go
++++ b/db.go
+@@ -36,6 +36,9 @@ const (
+    DefaultAllocSize         = 16 * 1024 * 1024
+ )
+ 
++// default page size for db is set to the OS page size.
++var defaultPageSize = os.Getpagesize()
++
+ // DB represents a collection of buckets persisted to a file on disk.
+ // All data access is performed through transactions which can be obtained through the DB.
+ // All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called.
+@@ -320,7 +323,7 @@ func (db *DB) mmapSize(size int) (int, error) {
+ // init creates a new database file and initializes its meta pages.
+ func (db *DB) init() error {
+    // Set the page size to the OS page size.
+-   db.pageSize = os.Getpagesize()
++   db.pageSize = defaultPageSize
+ 
+    // Create two meta pages on a buffer.
+    buf := make([]byte, db.pageSize*4)
+@@ -779,10 +782,21 @@ func (db *DB) meta() *meta {
+    return db.meta1
+ }
+ 
++var pagePool = sync.Pool{
++   New: func() interface{} {
++       return make([]byte, defaultPageSize)
++   },
++}
++
+ // allocate returns a contiguous block of memory starting at a given page.
+ func (db *DB) allocate(count int) (*page, error) {
+    // Allocate a temporary buffer for the page.
+-   buf := make([]byte, count*db.pageSize)
++   var buf []byte
++   if count == 1 && db.pageSize == defaultPageSize {
++       buf = pagePool.Get().([]byte)
++   } else {
++       buf = make([]byte, count*db.pageSize)
++   }
+    p := (*page)(unsafe.Pointer(&buf[0]))
+    p.overflow = uint32(count - 1)
+ 
+diff --git a/tx.go b/tx.go
+index e74d2cae..09a39fb0 100644
+--- a/tx.go
++++ b/tx.go
+@@ -441,6 +441,8 @@ func (tx *Tx) write() error {
+    for _, p := range tx.pages {
+        pages = append(pages, p)
+    }
++   // Clear out page cache early.
++   tx.pages = make(map[pgid]*page)
+    sort.Sort(pages)
+ 
+    // Write pages to disk in order.
+@@ -485,8 +487,18 @@ func (tx *Tx) write() error {
+        }
+    }
+ 
+-   // Clear out page cache.
+-   tx.pages = make(map[pgid]*page)
++   // put small pages back to sync.Pool
++   for _, p := range pages {
++       if int(p.overflow) != 0 || tx.db.pageSize != defaultPageSize {
++           continue
++       }
++       buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:defaultPageSize]
++       // See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1
++       for i := range buf {
++           buf[i] = 0
++       }
++       pagePool.Put(buf)
++   }
+ 
+    return nil
+ }

.idea/go-gitdiff.iml

@@ -90,14 +90,14 @@ func (f *TextFragment) FuncNames() []string {
 		// func (this *Object) NAME(arg1, arg2, ...)
 		low := strings.Index(def, ")") + 2
 		if low >= len(def) {
-			log.Printf("Can't handle '%s'"， def)
+			log.Printf("Can't handle '%s'", def)
 			return
 		}
 		hig := strings.Index(def[low:], "(") + low
 		if low < hig && low >= 0 && hig < len(def) {
 			funcnames = append(funcnames, def[low:hig])
 		} else {
-			log.Printf("Can't handle '%s'"， def)
+			log.Printf("Can't handle '%s'", def)
 		}
 	}
 	addname(f.Comment)

.idea/misc.xml

@@ -60,6 +60,7 @@ func (p *Patches) GetCommit(file *File) (Commit, bool) {
 	return cmt, ok
 }
 
+
 func ParsePatch(r io.Reader) ([]*File, *Patches, error) {
 	p := newParser(r)
 	patches := &Patches{

.idea/modules.xml

@@ -0,0 +1,31 @@
+package main
+
+import (
+    "fmt"
+    "github.com/timmyyuan/go-gitdiff/gitdiff"
+    "log"
+    "os"
+)
+
+func main() {
+    patch, err := os.Open("changes.patch")
+    if err != nil {
+        log.Fatal(err)
+    }
+
+    _, ps, err := gitdiff.ParsePatch(patch)
+    if err != nil {
+        log.Fatal(err)
+    }
+    for k, v := range ps.ShaToFiles {
+        log.Printf("%s : \n", k)
+        for _, f := range v {
+            for _, frag := range f.TextFragments {
+                funcnames := frag.FuncNames()
+                for _, name := range funcnames {
+                    fmt.Printf("%s, ", name)
+                }
+            }
+        }
+    }
+}