Only bind fuse wrappers into fuse_operations for functions that have overrides in a deriving class

1 files changed, 100 insertions, 4 deletions

diff --git a/libfusepp/fuseapp.h b/libfusepp/fuseapp.h
index 1c94f13..bb18c02 100644
--- a/libfusepp/fuseapp.h
+++ b/libfusepp/fuseapp.h
@@ -3,7 +3,10 @@
 
 #define FUSE_USE_VERSION 26
 #include <fuse.h>
+#include <typeinfo>
 #include <exception>
+#include <stdio.h>
+#include <errno.h>
 
 class FuseAppBase {
 	public:
@@ -47,12 +50,105 @@ class FuseAppBase {
 		virtual int bmap(const char *, size_t blocksize, uint64_t *idx);
 		virtual int ioctl(const char *, int cmd, void *arg, struct fuse_file_info *, unsigned int flags, void * data);
 		virtual int poll(const char *, struct fuse_file_info *, struct fuse_pollhandle *, unsigned *);
-		virtual int write_buf (const char *, struct fuse_bufvec *buf, off_t off, struct fuse_file_info *);
-		virtual int read_buf (const char *, struct fuse_bufvec **bufp, size_t size, off_t off, struct fuse_file_info *);
-		virtual int flock (const char *, struct fuse_file_info *, int op);
+		virtual int write_buf(const char *, struct fuse_bufvec *buf, off_t off, struct fuse_file_info *);
+		virtual int read_buf(const char *, struct fuse_bufvec **bufp, size_t size, off_t off, struct fuse_file_info *);
+		virtual int flock(const char *, struct fuse_file_info *, int op);
+		virtual int fallocate(const char *, int, off_t, off_t, struct fuse_file_info *);
 		virtual int onError(const std::exception & err) throw();
 
-		static int run(int &, char ** &, FuseAppBase *);
+#define IFIMPL(func) typeid(&FuseAppBase::func) == typeid(&FuseApp::func) ? NULL :
+		template <typename FuseApp>
+		static int run(int & argc, char** & argv, FuseApp * fa)
+		{
+			auto args = runint(argc, argv, fa);
+			struct fuse_operations operations = {
+				IFIMPL(getattr) fuseCall<const char *, struct stat *>::helper<&FuseAppBase::getattr>,
+				IFIMPL(readlink) fuseCall<const char *, char *, size_t>::helper<&FuseAppBase::readlink>,
+				NULL, // getdir deprecated
+				IFIMPL(mknod) fuseCall<const char *, mode_t, dev_t>::helper<&FuseAppBase::mknod>,
+				IFIMPL(mkdir) fuseCall<const char *, mode_t>::helper<&FuseAppBase::mkdir>,
+				IFIMPL(unlink) fuseCall<const char *>::helper<&FuseAppBase::unlink>,
+				IFIMPL(rmdir) fuseCall<const char *>::helper<&FuseAppBase::rmdir>,
+				IFIMPL(symlink) fuseCall<const char *, const char *>::helper<&FuseAppBase::symlink>,
+				IFIMPL(rename) fuseCall<const char *, const char *>::helper<&FuseAppBase::rename>,
+				IFIMPL(link) fuseCall<const char *, const char *>::helper<&FuseAppBase::link>,
+				IFIMPL(chmod) fuseCall<const char *, mode_t>::helper<&FuseAppBase::chmod>,
+				IFIMPL(chown) fuseCall<const char *, uid_t, gid_t>::helper<&FuseAppBase::chown>,
+				IFIMPL(truncate) fuseCall<const char *, off_t>::helper<&FuseAppBase::truncate>,
+				NULL, // utime deprecated
+				IFIMPL(open) fuseCall<const char *, struct fuse_file_info *>::helper<&FuseAppBase::open>,
+				IFIMPL(read) fuseCall<const char *, char *, size_t, off_t, struct fuse_file_info *>::helper<&FuseAppBase::read>,
+				IFIMPL(write) fuseCall<const char *, const char *, size_t, off_t, struct fuse_file_info *>::helper<&FuseAppBase::write>,
+				IFIMPL(statfs) fuseCall<const char *, struct statvfs *>::helper<&FuseAppBase::statfs>,
+				IFIMPL(flush) fuseCall<const char *, struct fuse_file_info *>::helper<&FuseAppBase::flush>,
+				IFIMPL(release) fuseCall<const char *, struct fuse_file_info *>::helper<&FuseAppBase::release>,
+				IFIMPL(fsync) fuseCall<const char *, int, struct fuse_file_info *>::helper<&FuseAppBase::fsync>,
+				IFIMPL(setxattr) fuseCall<const char *, const char *, const char *, size_t, int>::helper<&FuseAppBase::setxattr>,
+				IFIMPL(getxattr) fuseCall<const char *, const char *, char *, size_t>::helper<&FuseAppBase::getxattr>,
+				IFIMPL(listxattr) fuseCall<const char *, char *, size_t>::helper<&FuseAppBase::listxattr>,
+				IFIMPL(removexattr) fuseCall<const char *, const char *>::helper<&FuseAppBase::removexattr>,
+				IFIMPL(opendir) fuseCall<const char *, struct fuse_file_info *>::helper<&FuseAppBase::opendir>,
+				IFIMPL(readdir) fuseCall<const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *>::helper<&FuseAppBase::readdir>,
+				IFIMPL(releasedir) fuseCall<const char *, struct fuse_file_info *>::helper<&FuseAppBase::releasedir>,
+				IFIMPL(fsyncdir) fuseCall<const char *, int, struct fuse_file_info *>::helper<&FuseAppBase::fsyncdir>,
+				fuseInit,
+				fuseDestroy,
+				IFIMPL(access) fuseCall<const char *, int>::helper<&FuseAppBase::access>,
+				IFIMPL(create) fuseCall<const char *, mode_t, struct fuse_file_info *>::helper<&FuseAppBase::create>,
+				IFIMPL(fgetattr) fuseCall<const char *, off_t, struct fuse_file_info *>::helper<&FuseAppBase::ftruncate>,
+				IFIMPL(fgetattr) fuseCall<const char *, struct stat *, struct fuse_file_info *>::helper<&FuseAppBase::fgetattr>,
+#if (FUSE_MINOR_VERSION >= 6)
+				IFIMPL(lock) fuseCall<const char *, struct fuse_file_info *, int, struct flock *>::helper<&FuseAppBase::lock>,
+				IFIMPL(utimens) fuseCall<const char *, const struct timespec [2]>::helper<&FuseAppBase::utimens>,
+				IFIMPL(bmap) fuseCall<const char *, size_t, uint64_t *>::helper<&FuseAppBase::bmap>,
+#if (FUSE_MINOR_VERSION >= 8)
+				0, // flag_nullpath_ok
+#if (FUSE_MINOR_VERSION >= 9)
+				0, // flag_nopath
+				0, // flag_utime_omit_ok
+#endif
+				0, // flag_reserved
+				IFIMPL(ioctl) fuseCall<const char *, int, void *, struct fuse_file_info *, unsigned int, void *>::helper<&FuseAppBase::ioctl>,
+				IFIMPL(poll) fuseCall<const char *, struct fuse_file_info *, struct fuse_pollhandle *, unsigned *>::helper<&FuseAppBase::poll>,
+#if (FUSE_MINOR_VERSION >= 9)
+				IFIMPL(write_buf) fuseCall<const char *, struct fuse_bufvec *, off_t, struct fuse_file_info *>::helper<&FuseAppBase::write_buf>,
+				IFIMPL(read_buf) fuseCall<const char *, struct fuse_bufvec **, size_t, off_t, struct fuse_file_info *>::helper<&FuseAppBase::read_buf>,
+				IFIMPL(flock) fuseCall<const char *, struct fuse_file_info *, int>::helper<&FuseAppBase::flock>,
+				IFIMPL(fallocate) fuseCall<const char *, int, off_t, off_t, struct fuse_file_info *>::helper<&FuseAppBase::fallocate>,
+#endif
+#endif
+#endif
+			};
+			return fuse_main(args.argc, args.argv, &operations, fa);
+		}
+	private:
+		static struct fuse_args runint(int &, char ** &, FuseAppBase *);
+		static void * fuseInit(struct fuse_conn_info *conn);
+		static void fuseDestroy(void *);
+
+		template <typename... Args>
+		class fuseCall {
+			public:
+				template <int (FuseAppBase::*f)(Args...)>
+				static int helper(Args ... a)
+				{
+					try {
+						return (fuseApp->*f)(a...);
+					}
+					catch (const std::exception & ex) {
+						if (int rtn = fuseApp->onError(ex)) {
+							return rtn;
+						}
+						return helper<f>(a...);
+					}
+					catch (...) {
+						fprintf(stderr, "Unknown exception calling %s\n", typeid(f).name());
+						return -ENOSYS;
+					}
+				}
+		};
+
+		static FuseAppBase * fuseApp;
 };
 
 #endif