From 4da9416bec98e2702d8e78a194aa42725f55a267 Mon Sep 17 00:00:00 2001
From: Ben Sarmiento <ben.sarmiento@forto.com>
Date: Tue, 14 Nov 2023 16:55:24 +0100
Subject: [PATCH] Fix chunk manager

---
 cmd/zurg/main.go      | 12 ++++++------
 internal/zfs/zfs.go   | 11 ++++-------
 pkg/chunk/download.go | 11 ++++-------
 pkg/chunk/manager.go  | 15 ++++++++++-----
 4 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/cmd/zurg/main.go b/cmd/zurg/main.go
index 576726f..04f881d 100644
--- a/cmd/zurg/main.go
+++ b/cmd/zurg/main.go
@@ -67,12 +67,12 @@ func main() {
 	log.Debugf("Initializing chunk manager, cores: %d", runtime.NumCPU())
 	// 64kb request size
 	chunkMgr, err := chunk.NewManager(
-		"",
-		1048576,                    // 1MB
-		1,                          // 1 chunk - load ahead (1MB total)
-		max(runtime.NumCPU()/2, 1), // check threads
-		max(runtime.NumCPU()/2, 1), // load threads
-		runtime.NumCPU()*2,
+		"",                             // in-memory chunk file
+		5242880,                        // 10MB
+		max((runtime.NumCPU()/2)-1, 1), // 1 chunk - load ahead (1MB total)
+		max(runtime.NumCPU()/2, 1),     // check threads
+		max(runtime.NumCPU()/2, 1),     // load threads
+		runtime.NumCPU()*4,
 		torrentMgr, // max chunks
 		config)
 	if nil != err {
diff --git a/internal/zfs/zfs.go b/internal/zfs/zfs.go
index a043ccc..5ec7ae8 100644
--- a/internal/zfs/zfs.go
+++ b/internal/zfs/zfs.go
@@ -108,9 +108,6 @@ func (fs *ZurgFS) Read(path string, buff []byte, ofst int64, fh uint64) (n int)
 		return -fuse.ENOENT
 	} else {
 		size := int64(len(buff))
-		if size < int64(fs.Config.GetNetworkBufferSize()) {
-			size = int64(fs.Config.GetNetworkBufferSize())
-		}
 		endofst := ofst + size
 		if endofst > file.Bytes {
 			endofst = file.Bytes
@@ -118,14 +115,14 @@ func (fs *ZurgFS) Read(path string, buff []byte, ofst int64, fh uint64) (n int)
 		if endofst < ofst {
 			return 0
 		}
+		// let's request a bigger chunk than we need
+		if size < int64(fs.Config.GetNetworkBufferSize()) {
+			size = int64(fs.Config.GetNetworkBufferSize())
+		}
 		response, err := fs.Chunk.GetChunk(file, ofst, size)
 		if err != nil {
 			return -fuse.ENOENT
 		}
-		// response := universal.GetFileReader(torrent, file, ofst, int(size), fs.TorrentManager, fs.Config, fs.Log)
-		// if response == nil {
-		// 	return -fuse.ENOENT
-		// }
 		n = copy(buff, response[:endofst-ofst])
 		return n
 	}
diff --git a/pkg/chunk/download.go b/pkg/chunk/download.go
index c26be05..6f096a3 100644
--- a/pkg/chunk/download.go
+++ b/pkg/chunk/download.go
@@ -8,7 +8,6 @@ import (
 	"syscall"
 	"time"
 
-	"github.com/debridmediamanager.com/zurg/internal/config"
 	"github.com/debridmediamanager.com/zurg/internal/torrent"
 	"github.com/debridmediamanager.com/zurg/pkg/logutil"
 	"go.uber.org/zap"
@@ -22,15 +21,14 @@ type Downloader struct {
 	callbacks  map[RequestID][]DownloadCallback
 	lock       sync.Mutex
 	storage    *Storage
-	c          config.ConfigInterface
-	t          *torrent.TorrentManager
+	torMgr     *torrent.TorrentManager
 	log        *zap.SugaredLogger
 }
 
 type DownloadCallback func(error, []byte)
 
 // NewDownloader creates a new download manager
-func NewDownloader(threads int, storage *Storage, bufferSize int64, t *torrent.TorrentManager, c config.ConfigInterface) (*Downloader, error) {
+func NewDownloader(threads int, storage *Storage, bufferSize int64, torMgr *torrent.TorrentManager) (*Downloader, error) {
 	rlog := logutil.NewLogger()
 	log := rlog.Named("downloader")
 
@@ -39,8 +37,7 @@ func NewDownloader(threads int, storage *Storage, bufferSize int64, t *torrent.T
 		queue:      make(chan *Request, 100),
 		callbacks:  make(map[RequestID][]DownloadCallback, 100),
 		storage:    storage,
-		c:          c,
-		t:          t,
+		torMgr:     torMgr,
 		log:        log,
 	}
 
@@ -105,7 +102,7 @@ func (d *Downloader) downloadFromAPI(request *Request, buffer []byte, delay int6
 		time.Sleep(time.Duration(delay) * time.Second)
 	}
 
-	resp := d.t.UnrestrictUntilOk(request.file.Link)
+	resp := d.torMgr.UnrestrictUntilOk(request.file.Link)
 	if resp == nil {
 		return fmt.Errorf("cannot unrestrict file %s %s", request.file.Path, request.file.Link)
 	}
diff --git a/pkg/chunk/manager.go b/pkg/chunk/manager.go
index 00011a4..4ac1334 100644
--- a/pkg/chunk/manager.go
+++ b/pkg/chunk/manager.go
@@ -1,9 +1,9 @@
 package chunk
 
 import (
-	"crypto/sha256"
 	"encoding/binary"
 	"fmt"
+	"hash/fnv"
 	"os"
 
 	"github.com/debridmediamanager.com/zurg/internal/config"
@@ -58,8 +58,8 @@ func NewManager(
 	checkThreads,
 	loadThreads,
 	maxChunks int,
-	t *torrent.TorrentManager,
-	c config.ConfigInterface) (*Manager, error) {
+	torMgr *torrent.TorrentManager,
+	cfg config.ConfigInterface) (*Manager, error) {
 
 	pageSize := int64(os.Getpagesize())
 	if chunkSize < pageSize {
@@ -82,7 +82,7 @@ func NewManager(
 		return nil, err
 	}
 
-	downloader, err := NewDownloader(loadThreads, storage, chunkSize, t, c)
+	downloader, err := NewDownloader(loadThreads, storage, chunkSize, torMgr)
 	if nil != err {
 		return nil, err
 	}
@@ -149,12 +149,17 @@ func buildRequestID(object *torrent.File, offset int64) (id RequestID) {
 	if fileID == "" {
 		fileID = object.Path
 	}
-	hash := sha256.Sum256([]byte(fileID))
+	hash := hashStringToFh(fileID)
 	copy(id[:16], hash[:16])
 	binary.BigEndian.PutUint64(id[16:], uint64(offset))
 	return
 }
 
+func hashStringToFh(s string) []byte {
+	hasher := fnv.New64a()
+	return hasher.Sum([]byte(s))
+}
+
 func (m *Manager) requestChunk(object *torrent.File, offset, size int64, sequence int, preload bool, response chan Response) {
 	chunkOffset := offset % m.ChunkSize
 	offsetStart := offset - chunkOffset