From 67e137a474ef7fd18b03599c41d5545c121eca61 Mon Sep 17 00:00:00 2001
From: Caj Larsson <git-mail@caj.me>
Date: Tue, 3 May 2022 18:45:06 +0800
Subject: [PATCH] fix: #8 content size lies

---
 dataswamp/namespace/valueobjects.go |  6 +++++-
 dataswamp/services.go               | 17 ++++++++++++++++-
 dataswamp/services_test.go          | 28 ++++++++++++++++++++++++++++
 dataswamp/swampfile/entities.go     | 16 +++++++++-------
 4 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/dataswamp/namespace/valueobjects.go b/dataswamp/namespace/valueobjects.go
index eb7f0c5..5b0e4a6 100644
--- a/dataswamp/namespace/valueobjects.go
+++ b/dataswamp/namespace/valueobjects.go
@@ -6,7 +6,11 @@ type FileSizeQuota struct {
 }
 
 func (f *FileSizeQuota) Allows(size int64) bool {
-	return f.CurrentUsage+size <= f.AllowanceKB
+	return f.Remaining() >= size
+}
+
+func (f *FileSizeQuota) Remaining() int64 {
+	return f.AllowanceKB - f.CurrentUsage
 }
 
 func (f *FileSizeQuota) Add(size int64) error {
diff --git a/dataswamp/services.go b/dataswamp/services.go
index 6dcca34..f921f84 100644
--- a/dataswamp/services.go
+++ b/dataswamp/services.go
@@ -73,7 +73,22 @@ func (s SwampFileService) SaveFile(ref swampfile.FileReference, src io.Reader, s
 		return err
 	}
 
-	io.Copy(f, src)
+	written, err := io.CopyN(f, src, size)
+
+	if written < size {
+		s.swamp_file_repo.Delete(ref.Path, strconv.FormatInt(ns.ID, 10))
+		return swampfile.ErrContentSizeExaggerated
+	}
+
+	var buf = make([]byte, 1)
+
+	overread, err :=src.Read(buf)
+
+	if overread > 0 || err != io.EOF {
+		s.swamp_file_repo.Delete(ref.Path, strconv.FormatInt(ns.ID, 10))
+		return swampfile.ErrContentSizeExceeded
+	}
+
 	f.Close()
 	ns.FileQuota.Add(size)
 	s.namespace_repo.Update(ns.ID, *ns)
diff --git a/dataswamp/services_test.go b/dataswamp/services_test.go
index b63deea..c6a8d34 100644
--- a/dataswamp/services_test.go
+++ b/dataswamp/services_test.go
@@ -105,3 +105,31 @@ func TestPathStrictMode(t *testing.T) {
 	err = s.SaveFile(ref, ns_file, int64(ns_file.Len()))
 	is.Equal(err, swampfile.ErrUnacceptablePath)
 }
+
+
+func TestQuotaWithContenSizeLieOver(t *testing.T) {
+	is := is.New(t)
+	s := NewTestSwampFileService()
+
+	largefakefile := bytes.NewBufferString("")
+
+	for largefakefile.Len() < 64000 {
+		_, _ = largefakefile.WriteString("A very repetitive file")
+	}
+
+	err := s.SaveFile(file_ref3, largefakefile, int64(10))
+
+	is.Equal(err, swampfile.ErrContentSizeExceeded)
+}
+
+
+func TestQuotaWithContenSizeLieUnder(t *testing.T) {
+	is := is.New(t)
+	s := NewTestSwampFileService()
+
+	largefakefile := bytes.NewBufferString("small")
+
+	err := s.SaveFile(file_ref3, largefakefile, int64(1024))
+
+	is.Equal(err, swampfile.ErrContentSizeExaggerated)
+}
diff --git a/dataswamp/swampfile/entities.go b/dataswamp/swampfile/entities.go
index 5f51a61..bbab94c 100644
--- a/dataswamp/swampfile/entities.go
+++ b/dataswamp/swampfile/entities.go
@@ -13,11 +13,13 @@ type SwampFile struct {
 }
 
 var (
-	ErrDuplicate        = errors.New("record already exists")
-	ErrExceedQuota      = errors.New("file too large")
-	ErrQuotaInvalid     = errors.New("quota invalid")
-	ErrNotExists        = errors.New("row not exists")
-	ErrUpdateFailed     = errors.New("update failed")
-	ErrDeleteFailed     = errors.New("delete failed")
-	ErrUnacceptablePath = errors.New("unacceptable path")
+	ErrDuplicate              = errors.New("record already exists")
+	ErrExceedQuota            = errors.New("file too large")
+	ErrQuotaInvalid           = errors.New("quota invalid")
+	ErrContentSizeExceeded    = errors.New("content size exceeded")
+	ErrContentSizeExaggerated = errors.New("content size exaggerated")
+	ErrNotExists              = errors.New("row not exists")
+	ErrUpdateFailed           = errors.New("update failed")
+	ErrDeleteFailed           = errors.New("delete failed")
+	ErrUnacceptablePath       = errors.New("unacceptable path")
 )