/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006 Christian Grothoff (and other contributing authors)
+ (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
* @file include/gnunet_disk_lib.h
* @brief disk IO apis
*/
-
#ifndef GNUNET_DISK_LIB_H
#define GNUNET_DISK_LIB_H
-#include "gnunet_configuration_lib.h"
-#include "gnunet_scheduler_lib.h"
+#if WINDOWS
+#define OFF_T uint64_t
+#else
+#define OFF_T off_t
+#endif
+
+/**
+ * Opaque handle used to access files.
+ */
+struct GNUNET_DISK_FileHandle;
+
+/**
+ * Handle used to manage a pipe.
+ */
+struct GNUNET_DISK_PipeHandle;
+
+
+enum GNUNET_FILE_Type
+{
+ GNUNET_DISK_FILE, GNUNET_PIPE
+};
+
+/**
+ * Handle used to access files (and pipes).
+ */
+struct GNUNET_DISK_FileHandle
+{
+
+#if WINDOWS
+ /**
+ * File handle under W32.
+ */
+ HANDLE h;
+
+ /**
+ * Type
+ */
+ enum GNUNET_FILE_Type type;
+
+ /**
+ * Structure for overlapped reading (for pipes)
+ */
+ OVERLAPPED *oOverlapRead;
+
+ /**
+ * Structure for overlapped writing (for pipes)
+ */
+ OVERLAPPED *oOverlapWrite;
+#else
+
+ /**
+ * File handle on other OSes.
+ */
+ int fd;
+
+#endif /*
+ */
+};
+
/* we need size_t, and since it can be both unsigned int
or unsigned long long, this IS platform dependent;
but "stdlib.h" should be portable 'enough' to be
unconditionally available... */
#include <stdlib.h>
+#include "gnunet_configuration_lib.h"
+#include "gnunet_scheduler_lib.h"
#ifdef __cplusplus
extern "C"
#endif
#endif
+
+/**
+ * Specifies how a file should be opened.
+ */
+enum GNUNET_DISK_OpenFlags
+{
+
+ /**
+ * Open the file for reading
+ */
+ GNUNET_DISK_OPEN_READ = 1,
+
+ /**
+ * Open the file for writing
+ */
+ GNUNET_DISK_OPEN_WRITE = 2,
+
+ /**
+ * Open the file for both reading and writing
+ */
+ GNUNET_DISK_OPEN_READWRITE = 3,
+
+ /**
+ * Fail if file already exists
+ */
+ GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
+
+ /**
+ * Truncate file if it exists
+ */
+ GNUNET_DISK_OPEN_TRUNCATE = 8,
+
+ /**
+ * Create file if it doesn't exist
+ */
+ GNUNET_DISK_OPEN_CREATE = 16,
+
+ /**
+ * Append to the file
+ */
+ GNUNET_DISK_OPEN_APPEND = 32
+};
+
+/**
+ * Specifies what type of memory map is desired.
+ */
+enum GNUNET_DISK_MapType
+{
+ /**
+ * Read-only memory map.
+ */
+ GNUNET_DISK_MAP_TYPE_READ = 1,
+
+ /**
+ * Write-able memory map.
+ */
+ GNUNET_DISK_MAP_TYPE_WRITE = 2,
+ /**
+ * Read-write memory map.
+ */
+ GNUNET_DISK_MAP_TYPE_READWRITE = 3
+};
+
+
+/**
+ * File access permissions, UNIX-style.
+ */
+enum GNUNET_DISK_AccessPermissions
+{
+ /**
+ * Nobody is allowed to do anything to the file.
+ */
+ GNUNET_DISK_PERM_NONE = 0,
+
+ /**
+ * Owner can read.
+ */
+ GNUNET_DISK_PERM_USER_READ = 1,
+
+ /**
+ * Owner can write.
+ */
+ GNUNET_DISK_PERM_USER_WRITE = 2,
+
+ /**
+ * Owner can execute.
+ */
+ GNUNET_DISK_PERM_USER_EXEC = 4,
+
+ /**
+ * Group can read.
+ */
+ GNUNET_DISK_PERM_GROUP_READ = 8,
+
+ /**
+ * Group can write.
+ */
+ GNUNET_DISK_PERM_GROUP_WRITE = 16,
+
+ /**
+ * Group can execute.
+ */
+ GNUNET_DISK_PERM_GROUP_EXEC = 32,
+
+ /**
+ * Everybody can read.
+ */
+ GNUNET_DISK_PERM_OTHER_READ = 64,
+
+ /**
+ * Everybody can write.
+ */
+ GNUNET_DISK_PERM_OTHER_WRITE = 128,
+
+ /**
+ * Everybody can execute.
+ */
+ GNUNET_DISK_PERM_OTHER_EXEC = 256
+};
+
+
+/**
+ * Constants for specifying how to seek.
+ */
+enum GNUNET_DISK_Seek
+{
+ /**
+ * Seek an absolute position (from the start of the file).
+ */
+ GNUNET_DISK_SEEK_SET,
+
+ /**
+ * Seek a relative position (from the current offset).
+ */
+ GNUNET_DISK_SEEK_CUR,
+
+ /**
+ * Seek an absolute position from the end of the file.
+ */
+ GNUNET_DISK_SEEK_END
+};
+
+
+/**
+ * Enumeration identifying the two ends of a pipe.
+ */
+enum GNUNET_DISK_PipeEnd
+{
+ /**
+ * The reading-end of a pipe.
+ */
+ GNUNET_DISK_PIPE_END_READ = 0,
+
+ /**
+ * The writing-end of a pipe.
+ */
+ GNUNET_DISK_PIPE_END_WRITE = 1
+};
+
+
/**
* Get the number of blocks that are left on the partition that
* contains the given file (for normal users).
* @param part a file on the partition to check
* @return -1 on errors, otherwise the number of free blocks
*/
-long GNUNET_DISK_get_blocks_available (const char *part);
+long
+GNUNET_DISK_get_blocks_available (const char *part);
+
+
+/**
+ * Checks whether a handle is invalid
+ *
+ * @param h handle to check
+ * @return GNUNET_YES if invalid, GNUNET_NO if valid
+ */
+int
+GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
/**
* Check that fil corresponds to a filename
* (of a file that exists and that is not a directory).
*
- * @returns GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
+ * @param fil filename to check
+ * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
* else (will print an error message in that case, too).
*/
-int GNUNET_DISK_file_test (const char *fil);
+int
+GNUNET_DISK_file_test (const char *fil);
+
+
+/**
+ * Move the read/write pointer in a file
+ * @param h handle of an open file
+ * @param offset position to move to
+ * @param whence specification to which position the offset parameter relates to
+ * @return the new position on success, GNUNET_SYSERR otherwise
+ */
+OFF_T
+GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, OFF_T offset,
+ enum GNUNET_DISK_Seek whence);
/**
* Get the size of the file (or directory)
* of the given file (in bytes).
*
+ * @param filename name of the file or directory
+ * @param size set to the size of the file (or,
+ * in the case of directories, the sum
+ * of all sizes of files in the directory)
* @param includeSymLinks should symbolic links be
* included?
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_size (const char *filename, uint64_t * size,
+ int includeSymLinks);
+
+
+/**
+ * Obtain some unique identifiers for the given file
+ * that can be used to identify it in the local system.
+ * This function is used between GNUnet processes to
+ * quickly check if two files with the same absolute path
+ * are actually identical. The two processes represent
+ * the same peer but may communicate over the network
+ * (and the file may be on an NFS volume). This function
+ * may not be supported on all operating systems.
+ *
+ * @param filename name of the file
+ * @param dev set to the device ID
+ * @param ino set to the inode ID
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_DISK_file_get_identifiers (const char *filename, uint64_t * dev,
+ uint64_t * ino);
+
+
+/**
+ * Create an (empty) temporary file on disk. If the given name is not
+ * an absolute path, the current 'TMPDIR' will be prepended. In any case,
+ * 6 random characters will be appended to the name to create a unique
+ * filename.
+ *
+ * @param t component to use for the name;
+ * does NOT contain "XXXXXX" or "/tmp/".
+ * @return NULL on error, otherwise name of fresh
+ * file on disk in directory for temporary files
+ */
+char *
+GNUNET_DISK_mktemp (const char *t);
+
+
+/**
+ * Open a file. Note that the access permissions will only be
+ * used if a new file is created and if the underlying operating
+ * system supports the given permissions.
*
+ * @param fn file name to be opened
+ * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
+ * @param perm permissions for the newly created file, use
+ * GNUNET_DISK_PERM_NONE if a file could not be created by this
+ * call (because of flags)
+ * @return IO handle on success, NULL on error
+ */
+struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_file_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
+ enum GNUNET_DISK_AccessPermissions perm);
+
+
+/**
+ * Get the size of an open file.
+ *
+ * @param fh open file handle
+ * @param size where to write size of the file
* @return GNUNET_OK on success, GNUNET_SYSERR on error
*/
-int GNUNET_DISK_file_size (const char *filename,
- unsigned long long *size, int includeSymLinks);
+int
+GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
+ OFF_T *size);
+
+
+/**
+ * Creates an interprocess channel
+ * @param blocking creates an asynchronous pipe if set to GNUNET_NO
+ * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
+ * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
+ * @return handle to the new pipe, NULL on error
+ */
+struct GNUNET_DISK_PipeHandle *
+GNUNET_DISK_pipe (int blocking_read, int blocking_write, int inherit_read, int inherit_write);
/**
- * Wrapper around "open()". Opens a file.
+ * Creates a pipe object from a couple of file descriptors.
+ * Useful for wrapping existing pipe FDs.
+ *
+ * @param blocking creates an asynchronous pipe if set to GNUNET_NO
+ * @param fd an array of two fd values. One of them may be -1 for read-only or write-only pipes
*
- * @return file handle, -1 on error
+ * @return handle to the new pipe, NULL on error
*/
-int GNUNET_DISK_file_open (const char *filename, int oflag, ...);
+struct GNUNET_DISK_PipeHandle *
+GNUNET_DISK_pipe_from_fd (int blocking_read, int blocking_write, int fd[2]);
+/**
+ * Closes an interprocess channel
+ * @param p pipe
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
/**
- * Wrapper around "close()". Closes a file.
+ * Closes one half of an interprocess channel
+ *
+ * @param p pipe to close end of
+ * @param end which end of the pipe to close
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
*/
-void GNUNET_DISK_file_close (const char *filename, int fd);
+int
+GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
+ enum GNUNET_DISK_PipeEnd end);
+/**
+ * Close an open file.
+ *
+ * @param h file handle
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
+
+
+/**
+ * Get the handle to a particular pipe end
+ *
+ * @param p pipe
+ * @param n end to access
+ * @return handle for the respective end
+ */
+const struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
+ enum GNUNET_DISK_PipeEnd n);
/**
* Read the contents of a binary file into a buffer.
- * @param fileName the name of the file, not freed,
- * must already be expanded!
+ * @param h handle to an open file
+ * @param result the buffer to write the result to
* @param len the maximum number of bytes to read
+ * @return the number of bytes read on success, GNUNET_SYSERR on failure
+ */
+ssize_t
+GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
+ size_t len);
+
+/**
+ * Read the contents of a binary file into a buffer.
+ * Guarantees not to block (returns GNUNET_SYSERR and sets errno to EAGAIN
+ * when no data can be read).
+ *
+ * @param h handle to an open file
+ * @param result the buffer to write the result to
+ * @param len the maximum number of bytes to read
+ * @return the number of bytes read on success, GNUNET_SYSERR on failure
+ */
+ssize_t
+GNUNET_DISK_file_read_non_blocking (const struct GNUNET_DISK_FileHandle * h,
+ void *result, size_t len);
+
+/**
+ * Read the contents of a binary file into a buffer.
+ *
+ * @param fn file name
* @param result the buffer to write the result to
- * @return the number of bytes read on success, -1 on failure
+ * @param len the maximum number of bytes to read
+ * @return number of bytes read, GNUNET_SYSERR on failure
*/
-int GNUNET_DISK_file_read (const char *fileName, int len, void *result);
+ssize_t
+GNUNET_DISK_fn_read (const char *fn, void *result, size_t len);
/**
* Write a buffer to a file.
- * @param fileName the name of the file, NOT freed!
+ *
+ * @param h handle to open file
* @param buffer the data to write
* @param n number of bytes to write
- * @param mode the mode for file permissions
- * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ * @return number of bytes written on success, GNUNET_SYSERR on error
+ */
+ssize_t
+GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
+ const void *buffer, size_t n);
+
+
+/**
+ * Write a buffer to a file, blocking, if necessary.
+ * @param h handle to open file
+ * @param buffer the data to write
+ * @param n number of bytes to write
+ * @return number of bytes written on success, GNUNET_SYSERR on error
+ */
+ssize_t
+GNUNET_DISK_file_write_blocking (const struct GNUNET_DISK_FileHandle * h,
+ const void *buffer, size_t n);
+
+/**
+ * Write a buffer to a file. If the file is longer than
+ * the given buffer size, it will be truncated.
+ *
+ * @param fn file name
+ * @param buffer the data to write
+ * @param n number of bytes to write
+ * @param mode file permissions
+ * @return number of bytes written on success, GNUNET_SYSERR on error
*/
-int GNUNET_DISK_file_write (const char *fileName,
- const void *buffer, unsigned int n,
- const char *mode);
+ssize_t
+GNUNET_DISK_fn_write (const char *fn, const void *buffer, size_t n,
+ enum GNUNET_DISK_AccessPermissions mode);
/**
* Copy a file.
+ *
+ * @param src file to copy
+ * @param dst destination file name
* @return GNUNET_OK on success, GNUNET_SYSERR on error
*/
-int GNUNET_DISK_file_copy (const char *src, const char *dst);
+int
+GNUNET_DISK_file_copy (const char *src, const char *dst);
/**
- * Scan a directory for files. The name of the directory
- * must be expanded first (!).
+ * Scan a directory for files.
*
* @param dirName the name of the directory
* @param callback the method to call for each file
- * @param data argument to pass to callback
+ * @param callback_cls closure for callback
* @return the number of files found, -1 on error
*/
-int GNUNET_DISK_directory_scan (const char *dirName,
- GNUNET_FileNameCallback callback, void *data);
+int
+GNUNET_DISK_directory_scan (const char *dirName,
+ GNUNET_FileNameCallback callback,
+ void *callback_cls);
/**
*
* @param cls closure
* @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
- * get called on the next entry (or finish cleanly)
+ * get called on the next entry (or finish cleanly);
+ * NULL on error (will be the last call in that case)
* @param filename complete filename (absolute path)
* @param dirname directory name (absolute path)
*/
* GNUNET_NO if this was the last entry (and iteration is complete),
* GNUNET_SYSERR if "can" was YES
*/
-int GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator
- *iter, int can);
+int
+GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator *iter,
+ int can);
/**
* If a scheduler does not need to be used, GNUNET_DISK_directory_scan
* may provide a simpler API.
*
- * @param sched scheduler to use
* @param prio priority to use
* @param dirName the name of the directory
* @param callback the method to call for each file
* @param callback_cls closure for callback
+ * @return GNUNET_YES if directory is not empty and @callback
+ * will be called later, GNUNET_NO otherwise, GNUNET_SYSERR on error.
*/
-void GNUNET_DISK_directory_iterator_start (struct GNUNET_SCHEDULER_Handle
- *sched,
- enum GNUNET_SCHEDULER_Priority
- prio, const char *dirName,
- GNUNET_DISK_DirectoryIteratorCallback
- callback, void *callback_cls);
+int
+GNUNET_DISK_directory_iterator_start (enum GNUNET_SCHEDULER_Priority prio,
+ const char *dirName,
+ GNUNET_DISK_DirectoryIteratorCallback
+ callback, void *callback_cls);
/**
* @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
* GNUNET_NO if directory exists but is not writeable
*/
-int GNUNET_DISK_directory_create_for_file (const char *filename);
+int
+GNUNET_DISK_directory_create_for_file (const char *filename);
/**
- * Test if fil is a directory that can be accessed.
+ * Test if "fil" is a directory that can be accessed.
* Will not print an error message if the directory
* does not exist. Will log errors if GNUNET_SYSERR is
* returned.
*
+ * @param fil filename to test
* @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
* on any error and if exists but not directory
*/
-int GNUNET_DISK_directory_test (const char *fil);
+int
+GNUNET_DISK_directory_test (const char *fil);
/**
* @param fileName the file to remove
* @return GNUNET_OK on success, GNUNET_SYSERR on error
*/
-int GNUNET_DISK_directory_remove (const char *fileName);
+int
+GNUNET_DISK_directory_remove (const char *fileName);
/**
* @param dir the directory to create
* @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
*/
-int GNUNET_DISK_directory_create (const char *dir);
+int
+GNUNET_DISK_directory_create (const char *dir);
+
+
+/**
+ * Lock a part of a file.
+ *
+ * @param fh file handle
+ * @param lockStart absolute position from where to lock
+ * @param lockEnd absolute position until where to lock
+ * @param excl GNUNET_YES for an exclusive lock
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, OFF_T lockStart,
+ OFF_T lockEnd, int excl);
+
+
+/**
+ * Unlock a part of a file
+ * @param fh file handle
+ * @param unlockStart absolute position from where to unlock
+ * @param unlockEnd absolute position until where to unlock
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, OFF_T unlockStart,
+ OFF_T unlockEnd);
/**
* @brief Removes special characters as ':' from a filename.
* @param fn the filename to canonicalize
*/
-void GNUNET_DISK_filename_canonicalize (char *fn);
+void
+GNUNET_DISK_filename_canonicalize (char *fn);
/**
* @param user new owner of the file
* @return GNUNET_OK on success, GNUNET_SYSERR on failure
*/
-int GNUNET_DISK_file_change_owner (const char *filename, const char *user);
+int
+GNUNET_DISK_file_change_owner (const char *filename, const char *user);
/**
* a directory, end the last argument in '/' (or pass
* DIR_SEPARATOR_STR as the last argument before NULL).
*
+ * @param cfg configuration to use
* @param serviceName name of the service asking
- * @param varargs is NULL-terminated list of
+ * @param ... is NULL-terminated list of
* path components to append to the
* private directory name.
* @return the constructed filename
*/
-char *GNUNET_DISK_get_home_filename (struct GNUNET_CONFIGURATION_Handle *cfg,
- const char *serviceName, ...);
+char *
+GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ const char *serviceName, ...);
+
+
+/**
+ * Opaque handle for a memory-mapping operation.
+ */
+struct GNUNET_DISK_MapHandle;
+
+/**
+ * Map a file into memory
+ * @param h open file handle
+ * @param m handle to the new mapping (will be set)
+ * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
+ * @param len size of the mapping
+ * @return pointer to the mapped memory region, NULL on failure
+ */
+void *
+GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
+ struct GNUNET_DISK_MapHandle **m,
+ enum GNUNET_DISK_MapType access, size_t len);
+
+/**
+ * Unmap a file
+ *
+ * @param h mapping handle
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
+
+/**
+ * Write file changes to disk
+ * @param h handle to an open file
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
+
+/**
+ * Creates a named pipe/FIFO and opens it
+ * @param fn pointer to the name of the named pipe or to NULL
+ * @param flags open flags
+ * @param perm access permissions
+ * @return pipe handle on success, NULL on error
+ */
+struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_npipe_create (char **fn, enum GNUNET_DISK_OpenFlags flags,
+ enum GNUNET_DISK_AccessPermissions perm);
+
+/**
+ * Opens already existing named pipe/FIFO
+ *
+ * @param fn name of an existing named pipe
+ * @param flags open flags
+ * @param perm access permissions
+ * @return pipe handle on success, NULL on error
+ */
+struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_npipe_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
+ enum GNUNET_DISK_AccessPermissions perm);
+
+/**
+ * Closes a named pipe/FIFO
+ * @param pipe named pipe
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_npipe_close (struct GNUNET_DISK_FileHandle *pipe);
#if 0 /* keep Emacsens' auto-indent happy */
{
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