Merge pull request #2 from PDOK/add_cachsize_and_curl_logging_options

Allow user to configure cache size + cURL debug logging

README.md

@@ -1,26 +1,26 @@
 # go-cloud-sqlite-vfs
 
-# Description
+## Description
 
 This project wraps the [Cloud Backed SQLite](https://sqlite.org/cloudsqlite/doc/trunk/www/index.wiki) (CBS)
-solution into a golang package. The project uses [The SQLite OS Interface or "VFS"](https://www.sqlite.org/vfs.html)
+solution into a Go package. The project uses [The SQLite OS Interface or "VFS"](https://www.sqlite.org/vfs.html)
 concept to create a VFS which is backed by either Azure Blob Storage or Google Cloud Storage. The VFS can be used 
-with every SQLite golang package as long as it supports setting a custom VFS name.
+with every SQLite Go package as long as it supports setting a custom VFS name.
 
 Below are some examples about how to use this package, for further information about the workings of this package
 please read the [documentation](https://sqlite.org/cloudsqlite/doc/trunk/www/index.wiki) of the CBS project.
 
-# Installation
+## Installation
 
 This package can be installed with the `go get` command:
 
 ```bash
 go get github.com/PDOK/go-cloud-sqlite-vfs 
 ```
 
-**go-cloud-sqlite-vfs is cgo package**. If you want to build your app using go-cloud-sqlite-vfs , you need a C-compiler like gcc.
+**go-cloud-sqlite-vfs is cgo package**. If you want to build your app using go-cloud-sqlite-vfs, you need a C-compiler like gcc.
 
-# Usage
+## Usage
 
 ```go
 package main
@@ -64,9 +64,9 @@ func main() {
 }
 ```
 
-# Example project
+## Example project
 
-1. Build `blockcachevfsd` cli. For instuctions see the [CBS website](https://sqlite.org/cloudsqlite/doc/trunk/www/index.wiki)
+1. Build `blockcachevfsd` cli. For instructions see the [CBS website](https://sqlite.org/cloudsqlite/doc/trunk/www/index.wiki)
 2. Start Azurite
     ```bash
     docker run -p 10000:10000 mcr.microsoft.com/azure-storage/azurite azurite-blob --blobHost 0.0.0.0
@@ -89,7 +89,7 @@ func main() {
    go run ./
    ```
    
-# Dev
+## Dev
 
 Because the C code of the [CBS project](https://sqlite.org/cloudsqlite/dir?ci=tip) needs to be included in 
 the package it can be updated with the `download-c-code.sh` script located in the root of this project.

cloud_sqlite_vfs.go

@@ -18,6 +18,9 @@ import (
 	"unsafe"
 )
 
+var KEY = ""
+
+// VFS represent a SQLite virtual file systems backed by (Azure/Google) cloud object storage.
 type VFS struct {
 	bcvfs    *C.sqlite3_bcvfs
 	cacheDir string
@@ -26,8 +29,6 @@ type VFS struct {
 	Daemonless bool
 }
 
-var KEY = ""
-
 //export csAuthCb
 func csAuthCb(pCtx *C.void, zStorage *C.char, zAccount *C.char, zContainer *C.char, pzAuthToken **C.char) C.int {
 	cKey := C.CString(KEY)
@@ -43,16 +44,18 @@ func removeCacheDir(cacheDir string) error {
 
 func createCacheDir(cacheDir string) error {
 	if _, err := os.Stat(cacheDir); os.IsNotExist(err) {
-		err := os.Mkdir(cacheDir, 0750)
+		err = os.Mkdir(cacheDir, 0750)
 		if err != nil {
 			return err
 		}
 	}
-
 	return nil
 }
 
-func NewVFS(vfsName string, storage string, account string, key string, containerName string, cacheDir string) (VFS, error) {
+// NewVFS build a new VFS. Note: when provided cacheSize is 0 the default CBS cache size of 1Gb will be used
+func NewVFS(vfsName string, storage string, account string, key string,
+	containerName string, cacheDir string, cacheSize int64, curlVerbose bool) (VFS, error) {
+
 	KEY = key
 	vfs := &VFS{}
 
@@ -72,39 +75,44 @@ func NewVFS(vfsName string, storage string, account string, key string, containe
 	defer C.free(unsafe.Pointer(cCacheDir))
 	defer C.free(unsafe.Pointer(cVFSName))
 
-	if rc == C.SQLITE_OK {
-		if C.sqlite3_bcvfs_isdaemon(pVfs) == 1 {
-			vfs.Daemonless = false
-		} else {
-			vfs.Daemonless = true
-		}
-	} else {
+	if rc != C.SQLITE_OK {
 		_ = removeCacheDir(cacheDir)
 		return *vfs, fmt.Errorf("unable to create virtual filesystem with error: %s", C.GoString(zErr))
 	}
 
-	if rc == C.SQLITE_OK {
-		C.sqlite3_bcvfs_auth_callback(pVfs, nil, (*[0]byte)(unsafe.Pointer(C.csAuthCb)))
+	if curlVerbose {
+		C.sqlite3_bcvfs_config(pVfs, C.SQLITE_BCV_CURLVERBOSE, 1)
+	}
+	if C.sqlite3_bcvfs_isdaemon(pVfs) == 1 {
+		vfs.Daemonless = false
+	} else {
+		vfs.Daemonless = true
 
-		cStorage := C.CString(storage)
-		cAccount := C.CString(account)
-		cContainerName := C.CString(containerName)
+		if cacheSize > 0 {
+			// cache only works in daemonless mode
+			C.sqlite3_bcvfs_config(pVfs, C.SQLITE_BCV_CACHESIZE, C.longlong(cacheSize))
+		}
+	}
 
-		rc = C.sqlite3_bcvfs_attach(pVfs, cStorage, cAccount, cContainerName, nil, C.SQLITE_BCV_ATTACH_IFNOT, &zErr)
+	C.sqlite3_bcvfs_auth_callback(pVfs, nil, (*[0]byte)(unsafe.Pointer(C.csAuthCb)))
 
-		defer C.free(unsafe.Pointer(cStorage))
-		defer C.free(unsafe.Pointer(cAccount))
-		defer C.free(unsafe.Pointer(cContainerName))
+	cStorage := C.CString(storage)
+	cAccount := C.CString(account)
+	cContainerName := C.CString(containerName)
 
-		if rc != C.SQLITE_OK {
-			_ = removeCacheDir(cacheDir)
-			return *vfs, fmt.Errorf("unable to attach virtual filesystem with error: %s", C.GoString(zErr))
-		}
+	rc = C.sqlite3_bcvfs_attach(pVfs, cStorage, cAccount, cContainerName, nil, C.SQLITE_BCV_ATTACH_IFNOT, &zErr)
+
+	defer C.free(unsafe.Pointer(cStorage))
+	defer C.free(unsafe.Pointer(cAccount))
+	defer C.free(unsafe.Pointer(cContainerName))
+
+	if rc != C.SQLITE_OK {
+		_ = removeCacheDir(cacheDir)
+		return *vfs, fmt.Errorf("unable to attach virtual filesystem with error: %s", C.GoString(zErr))
 	}
 
 	vfs.bcvfs = pVfs
 	vfs.cacheDir = cacheDir
-
 	return *vfs, nil
 }
 

example/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+
 	"github.com/PDOK/go-cloud-sqlite-vfs"
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3"
@@ -23,7 +24,7 @@ type Genre struct {
 }
 
 func main() {
-	vfs, err := cloud_sqlite_vfs.NewVFS(VFS_NAME, STORAGE, ACCOUNT, KEY, CONTAINER_NAME, CACHE_DIR)
+	vfs, err := cloud_sqlite_vfs.NewVFS(VFS_NAME, STORAGE, ACCOUNT, KEY, CONTAINER_NAME, CACHE_DIR, 0, false)
 	if err != nil {
 		fmt.Println(err)
 		return