Started implementing reading/writing files

CryDevice.cpp

@@ -71,7 +71,7 @@ unique_ptr<fspp::Node> CryDevice::Load(const bf::path &path) {
   if (DirBlob::IsDir(*currentBlob)) {
     return make_unique<CryDir>(this, std::move(make_unique<DirBlob>(std::move(currentBlob))));
   } else if (FileBlob::IsFile(*currentBlob)) {
-    return make_unique<CryFile>(std::move(make_unique<FileBlob>(std::move(currentBlob))));
+    return make_unique<CryFile>(this, std::move(make_unique<FileBlob>(std::move(currentBlob))));
   } else {
     throw FuseErrnoException(EIO);
   }
@@ -85,4 +85,8 @@ unique_ptr<blobstore::Blob> CryDevice::CreateBlob() {
   return _blobStore->create();
 }
 
+unique_ptr<blobstore::Blob> CryDevice::LoadBlob(const blockstore::Key &key) {
+  return _blobStore->load(key);
+}
+
 }

CryDevice.h

@@ -25,6 +25,7 @@ public:
   void statfs(const boost::filesystem::path &path, struct ::statvfs *fsstat) override;
 
   std::unique_ptr<blobstore::Blob> CreateBlob();
+  std::unique_ptr<blobstore::Blob> LoadBlob(const blockstore::Key &key);
 
 private:
   blockstore::Key GetOrCreateRootKey(CryConfig *config);

CryDir.cpp

@@ -41,7 +41,7 @@ unique_ptr<fspp::File> CryDir::createFile(const string &name, mode_t mode) {
   //TODO Do we need a return value in createDir for fspp? If not, change fspp!
   auto fileblob = make_unique<FileBlob>(std::move(child));
   fileblob->InitializeEmptyFile();
-  return make_unique<CryFile>(std::move(fileblob));
+  return make_unique<CryFile>(_device, std::move(fileblob));
 }
 
 unique_ptr<fspp::Dir> CryDir::createDir(const string &name, mode_t mode) {

CryFile.cpp

@@ -15,15 +15,17 @@ using std::make_unique;
 
 namespace cryfs {
 
-CryFile::CryFile(unique_ptr<FileBlob> blob)
+CryFile::CryFile(CryDevice *device, unique_ptr<FileBlob> blob)
-: _blob(std::move(blob)) {
+: _device(device),
+  _blob(std::move(blob)) {
 }
 
 CryFile::~CryFile() {
 }
 
 unique_ptr<fspp::OpenFile> CryFile::open(int flags) const {
-  throw FuseErrnoException(ENOTSUP);
+  //TODO This is a performance issue because we open the blob twice on the "open" syscall
+  return make_unique<CryOpenFile>(make_unique<FileBlob>(_device->LoadBlob(_blob->key())));
 }
 
 void CryFile::stat(struct ::stat *result) const {

CryFile.h

@@ -11,7 +11,7 @@ namespace cryfs {
 
 class CryFile: public fspp::File, CryNode {
 public:
-  CryFile(std::unique_ptr<FileBlob> blob);
+  CryFile(CryDevice *device, std::unique_ptr<FileBlob> blob);
   virtual ~CryFile();
 
   void stat(struct ::stat *result) const override;
@@ -20,6 +20,7 @@ public:
   void unlink() override;
 
 private:
+  CryDevice *_device;
   std::unique_ptr<FileBlob> _blob;
 
   DISALLOW_COPY_AND_ASSIGN(CryFile);

CryOpenFile.cpp

@@ -5,17 +5,21 @@
 
 #include "CryDevice.h"
 #include "messmer/fspp/fuse/FuseErrnoException.h"
+#include "impl/FileBlob.h"
 
 namespace bf = boost::filesystem;
 
+using std::unique_ptr;
+using blobstore::Blob;
+
 //TODO Get rid of this in favor of a exception hierarchy
 using fspp::fuse::CHECK_RETVAL;
 using fspp::fuse::FuseErrnoException;
 
 namespace cryfs {
 
-CryOpenFile::CryOpenFile() {
+CryOpenFile::CryOpenFile(unique_ptr<FileBlob> fileBlob)
-  throw FuseErrnoException(ENOTSUP);
+: _fileBlob(std::move(fileBlob)) {
 }
 
 CryOpenFile::~CryOpenFile() {
@@ -35,11 +39,13 @@ void CryOpenFile::truncate(off_t size) const {
 }
 
 int CryOpenFile::read(void *buf, size_t count, off_t offset) {
-  throw FuseErrnoException(ENOTSUP);
+  //TODO Return number of read bytes
+  _fileBlob->read(buf, offset, count);
+  return count;
 }
 
 void CryOpenFile::write(const void *buf, size_t count, off_t offset) {
-  throw FuseErrnoException(ENOTSUP);
+  _fileBlob->write(buf, offset, count);
 }
 
 void CryOpenFile::fsync() {

CryOpenFile.h

@@ -7,10 +7,11 @@
 
 namespace cryfs {
 class CryDevice;
+class FileBlob;
 
 class CryOpenFile: public fspp::OpenFile {
 public:
-  CryOpenFile();
+  CryOpenFile(std::unique_ptr<FileBlob> fileBlob);
   virtual ~CryOpenFile();
 
   void stat(struct ::stat *result) const override;
@@ -22,6 +23,7 @@ public:
   void fdatasync() override;
 
 private:
+  std::unique_ptr<FileBlob> _fileBlob;
 
   DISALLOW_COPY_AND_ASSIGN(CryOpenFile);
 };

impl/FileBlob.cpp

@@ -1,6 +1,7 @@
 #include "FileBlob.h"
 
 #include "MagicNumbers.h"
+#include <messmer/blockstore/utils/Key.h>
 
 using std::unique_ptr;
 using blobstore::Blob;
@@ -34,4 +35,16 @@ bool FileBlob::IsFile(const Blob &blob) {
   return magicNumber(blob) == MagicNumbers::FILE;
 }
 
+void FileBlob::read(void *target, uint64_t offset, uint64_t count) const {
+  _blob->read(target, offset + 1, count);
+}
+
+void FileBlob::write(const void *source, uint64_t offset, uint64_t count) {
+  _blob->write(source, offset + 1, count);
+}
+
+blockstore::Key FileBlob::key() const {
+  	return _blob->key();
+  }
+
 }

impl/FileBlob.h

@@ -16,6 +16,11 @@ public:
 
   void InitializeEmptyFile();
 
+  void read(void *target, uint64_t offset, uint64_t count) const;
+  void write(const void *source, uint64_t offset, uint64_t count);
+
+  blockstore::Key key() const;
+
 private:
   std::unique_ptr<blobstore::Blob> _blob;