From f78bd14e286dfa94b52c37f3b620955eecce9d51 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Sun, 13 Feb 2022 14:25:38 +0100
Subject: [PATCH] repository: Remove pack implementation details from
 MasterIndex

---
 cmd/restic/cmd_prune.go             |  3 ++-
 cmd/restic/cmd_rebuild_index.go     |  3 ++-
 internal/checker/checker.go         |  2 +-
 internal/pack/pack.go               | 26 ++++++++++++++++++++++++++
 internal/repository/master_index.go | 22 ----------------------
 internal/restic/repository.go       |  1 -
 6 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/cmd/restic/cmd_prune.go b/cmd/restic/cmd_prune.go
index a03ae7474..76d7d7ea9 100644
--- a/cmd/restic/cmd_prune.go
+++ b/cmd/restic/cmd_prune.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
+	"github.com/restic/restic/internal/pack"
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 
@@ -245,7 +246,7 @@ func prune(opts PruneOptions, gopts GlobalOptions, repo restic.Repository, usedB
 	indexPack := make(map[restic.ID]packInfo)
 
 	// save computed pack header size
-	for pid, hdrSize := range repo.Index().PackSize(ctx, true) {
+	for pid, hdrSize := range pack.Size(ctx, repo.Index(), true) {
 		// initialize tpe with NumBlobTypes to indicate it's not set
 		indexPack[pid] = packInfo{tpe: restic.NumBlobTypes, usedSize: uint64(hdrSize)}
 	}
diff --git a/cmd/restic/cmd_rebuild_index.go b/cmd/restic/cmd_rebuild_index.go
index 718d2c767..0b3274ec4 100644
--- a/cmd/restic/cmd_rebuild_index.go
+++ b/cmd/restic/cmd_rebuild_index.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/restic/restic/internal/pack"
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 
@@ -97,7 +98,7 @@ func rebuildIndex(opts RebuildIndexOptions, gopts GlobalOptions, repo *repositor
 		if err != nil {
 			return err
 		}
-		packSizeFromIndex = repo.Index().PackSize(ctx, false)
+		packSizeFromIndex = pack.Size(ctx, repo.Index(), false)
 	}
 
 	Verbosef("getting pack files to read...\n")
diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index 5262789d0..c2a900420 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -123,7 +123,7 @@ func (c *Checker) LoadIndex(ctx context.Context) (hints []error, errs []error) {
 	}
 
 	// compute pack size using index entries
-	c.packs = c.masterIndex.PackSize(ctx, false)
+	c.packs = pack.Size(ctx, c.masterIndex, false)
 
 	debug.Log("checking for duplicate packs")
 	for packID := range c.packs {
diff --git a/internal/pack/pack.go b/internal/pack/pack.go
index 95f298acb..0c42f9ca2 100644
--- a/internal/pack/pack.go
+++ b/internal/pack/pack.go
@@ -1,6 +1,7 @@
 package pack
 
 import (
+	"context"
 	"encoding/binary"
 	"fmt"
 	"io"
@@ -317,3 +318,28 @@ func parseHeaderEntry(p []byte) (b restic.Blob, err error) {
 
 	return b, nil
 }
+
+func CalculateHeaderSize(blobs []restic.Blob) int {
+	return HeaderSize + len(blobs)*int(EntrySize)
+}
+
+// Size returns the size of all packs computed by index information.
+// If onlyHdr is set to true, only the size of the header is returned
+// Note that this function only gives correct sizes, if there are no
+// duplicates in the index.
+func Size(ctx context.Context, mi restic.MasterIndex, onlyHdr bool) map[restic.ID]int64 {
+	packSize := make(map[restic.ID]int64)
+
+	for blob := range mi.Each(ctx) {
+		size, ok := packSize[blob.PackID]
+		if !ok {
+			size = HeaderSize
+		}
+		if !onlyHdr {
+			size += int64(blob.Length)
+		}
+		packSize[blob.PackID] = size + int64(EntrySize)
+	}
+
+	return packSize
+}
diff --git a/internal/repository/master_index.go b/internal/repository/master_index.go
index adc110df8..9056528a2 100644
--- a/internal/repository/master_index.go
+++ b/internal/repository/master_index.go
@@ -6,7 +6,6 @@ import (
 	"sync"
 
 	"github.com/restic/restic/internal/debug"
-	"github.com/restic/restic/internal/pack"
 	"github.com/restic/restic/internal/restic"
 	"github.com/restic/restic/internal/ui/progress"
 	"golang.org/x/sync/errgroup"
@@ -131,27 +130,6 @@ func (mi *MasterIndex) Packs(packBlacklist restic.IDSet) restic.IDSet {
 	return packs
 }
 
-// PackSize returns the size of all packs computed by index information.
-// If onlyHdr is set to true, only the size of the header is returned
-// Note that this function only gives correct sizes, if there are no
-// duplicates in the index.
-func (mi *MasterIndex) PackSize(ctx context.Context, onlyHdr bool) map[restic.ID]int64 {
-	packSize := make(map[restic.ID]int64)
-
-	for blob := range mi.Each(ctx) {
-		size, ok := packSize[blob.PackID]
-		if !ok {
-			size = pack.HeaderSize
-		}
-		if !onlyHdr {
-			size += int64(blob.Length)
-		}
-		packSize[blob.PackID] = size + int64(pack.EntrySize)
-	}
-
-	return packSize
-}
-
 // Count returns the number of blobs of type t in the index.
 func (mi *MasterIndex) Count(t restic.BlobType) (n uint) {
 	mi.idxMutex.RLock()
diff --git a/internal/restic/repository.go b/internal/restic/repository.go
index 5e132157c..35f2f997b 100644
--- a/internal/restic/repository.go
+++ b/internal/restic/repository.go
@@ -70,7 +70,6 @@ type MasterIndex interface {
 	Has(BlobHandle) bool
 	Lookup(BlobHandle) []PackedBlob
 	Count(BlobType) uint
-	PackSize(ctx context.Context, onlyHdr bool) map[ID]int64
 
 	// Each returns a channel that yields all blobs known to the index. When
 	// the context is cancelled, the background goroutine terminates. This