From e11f761ecea3e44a632fd92e824a8c88fc5ac1ae Mon Sep 17 00:00:00 2001
From: icedream <icedream@icedream.pw>
Date: Sun, 26 Feb 2017 02:23:44 +0100
Subject: [PATCH] Add raw subpackage.

---
 raw/diff/diff.go   | 29 +++++++++++++++++++++++++++++
 raw/doc.go         |  5 +++++
 raw/patch/patch.go | 30 ++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 raw/diff/diff.go
 create mode 100644 raw/doc.go
 create mode 100644 raw/patch/patch.go

diff --git a/raw/diff/diff.go b/raw/diff/diff.go
new file mode 100644
index 0000000..2a585b3
--- /dev/null
+++ b/raw/diff/diff.go
@@ -0,0 +1,29 @@
+package diff
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/icedream/go-bsdiff/internal/native"
+)
+
+/*
+Diff generates a raw patch from old content that will be read in completely from
+oldReader and new content that will be read in completely from newReader and
+saves that patch to patchWriter.
+
+It may be helpful to save away the new content size along with the actual
+patch as it will be needed in order to reuse the patch.
+*/
+func Diff(oldReader, newReader io.Reader, patchWriter io.Writer) (err error) {
+	oldBytes, err := ioutil.ReadAll(oldReader)
+	if err != nil {
+		return
+	}
+	newBytes, err := ioutil.ReadAll(newReader)
+	if err != nil {
+		return
+	}
+
+	return native.Diff(oldBytes, newBytes, patchWriter)
+}
diff --git a/raw/doc.go b/raw/doc.go
new file mode 100644
index 0000000..da5810c
--- /dev/null
+++ b/raw/doc.go
@@ -0,0 +1,5 @@
+/*
+This subpackage directly exposes bsdiff functionality without any
+file format or compression code wrapped around it.
+*/
+package raw
diff --git a/raw/patch/patch.go b/raw/patch/patch.go
new file mode 100644
index 0000000..7aa6f27
--- /dev/null
+++ b/raw/patch/patch.go
@@ -0,0 +1,30 @@
+package patch
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/icedream/go-bsdiff/internal/native"
+)
+
+/*
+Patch reads a raw patch from patchReader and applies it on top of the old
+content which will be read from oldReader, saving the resulting new content to
+newWriter.
+
+newSize needs to be exactly the size of the new file that should be generated
+from the patch.
+*/
+func Patch(oldReader io.Reader, newWriter io.Writer, patchReader io.Reader, newSize uint64) (err error) {
+	oldBytes, err := ioutil.ReadAll(oldReader)
+	if err != nil {
+		return
+	}
+
+	newBytes := make([]byte, newSize)
+
+	err = native.Patch(oldBytes, newBytes, oldReader)
+
+	newWriter.Write(newBytes)
+	return
+}