/*
- * Copyright (c) 2005 Zmanda, Inc. All Rights Reserved.
+ * Copyright (c) 2005-2008 Zmanda Inc. All Rights Reserved.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 2.1 as
* along with this library; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
- * Contact information: Zmanda Inc., 505 N Mathlida Ave, Suite 120
- * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
+ * Contact information: Zmanda Inc., 465 S Mathlida Ave, Suite 300
+ * Sunnyvale, CA 94086, USA, or: http://www.zmanda.com
*/
/* The Device API abstracts device workings, interaction, properties, and
/*
* Type checking and casting macros
*/
+GType device_get_type (void);
#define TYPE_DEVICE (device_get_type())
#define DEVICE(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), device_get_type(), Device)
#define DEVICE_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), device_get_type(), Device const)
#define DEVICE_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), device_get_type(), DeviceClass)
#define IS_DEVICE(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), device_get_type ())
-
#define DEVICE_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), device_get_type(), DeviceClass)
typedef struct DevicePrivate_s DevicePrivate;
+/* This structure is a Flags (bitwise OR of values). Zero indicates success;
+ * any other value indicates some kind of problem reading the label. If
+ * multiple bits are set, it does not necessarily indicate that /all/ of
+ * the specified issues occured, but rather that /at least one/ did. */
+typedef enum {
+ /* When changing, Also update device_status_flags_values in
+ * device-src/device.c and perl/Amanda/Device.swg */
+ DEVICE_STATUS_SUCCESS = 0,
+
+ /* The device is in an unresolvable error state, and
+ * further retries are unlikely to change the status */
+ DEVICE_STATUS_DEVICE_ERROR = (1 << 0),
+
+ /* The device is in use, and should be retried later */
+ DEVICE_STATUS_DEVICE_BUSY = (1 << 1),
+
+ /* The device itself is OK, but has no media loaded. This
+ * may change if media is loaded by the user or a changer */
+ DEVICE_STATUS_VOLUME_MISSING = (1 << 2),
+
+ /* The device is OK and media is laoded, but there is
+ * no Amanda header or an invalid header on the media. */
+ DEVICE_STATUS_VOLUME_UNLABELED = (1 << 3),
+
+ /* The device is OK, but there was an unresolvable error
+ * loading the header from the media, so subsequent reads
+ * or writes will probably fail. */
+ DEVICE_STATUS_VOLUME_ERROR = (1 << 4),
+
+ DEVICE_STATUS_FLAGS_MAX = (1 << 5)
+} DeviceStatusFlags;
+
+#define DEVICE_STATUS_FLAGS_MASK (DEVICE_STATUS_MAX-1)
+#define DEVICE_STATUS_FLAGS_TYPE (device_status_flags_get_type())
+GType device_status_flags_get_type(void);
+
/*
* Main object structure
*/
-typedef struct {
+typedef struct Device {
GObject __parent__;
/* You can peek at the stuff below, but only subclasses should
change these values.*/
- /* What file, block are we at? (and are we in the middle of a
- * file?) This is automatically updated by
- * the default implementations of start_file, finish_file,
- * write_block, read_block, seek_file, and seek_block. */
+ /* What file, block are we at? (and are we in the middle of a * file?) */
int file;
guint64 block;
gboolean in_file;
- /* Holds the user-specified device name. */
+
+ /* Holds the user-specified device name, which may be an alias */
char * device_name;
- /* Holds the user-specified access-mode. */
+
+ /* Holds the user-specified access-mode, or ACCESS_NULL if the device
+ * has not yet been started*/
DeviceAccessMode access_mode;
+
/* In reading mode, FALSE unless all the data from the current file
- * was successfully read. */
+ * was successfully read. In writing mode, TRUE if the end of tape
+ * has been reached. */
gboolean is_eof;
+
/* Holds the label and time of the currently-inserted volume,
* or NULL if it has not been read/written yet. */
char * volume_label;
char * volume_time;
+ /* The most recently read volume header, or NULL if no header was
+ * read from this device. Callers can use this to glean information
+ * about the volume beyond volume_label and volume_time. */
+ dumpfile_t *volume_header;
+
+ /* The latest status for the device */
+ DeviceStatusFlags status;
+
+ /* device block-size ranges. These are also available as properties,
+ * and by default users can set block_size via property BLOCK_SIZE.
+ * Writers should use block_size, and readers should initially use
+ * block_size, and expand buffers as directed by read_block. */
+ gsize min_block_size;
+ gsize max_block_size;
+ gsize block_size;
+
+ /* surety and source for the block size; if you set block_size directly,
+ * set these, too! */
+ PropertySurety block_size_surety;
+ PropertySource block_size_source;
+
DevicePrivate * private;
} Device;
-/* Pointer to factory function for device types. The factory functions
- take control of their arguments, which should be dynamically
- allocated. The factory should call open_device() with this
- device_name. */
-typedef Device* (*DeviceFactory)(char * device_type,
- char * device_name);
+/* Pointer to factory function for device types.
+ *
+ * device_name is the full name ("tape:/dev/nst0")
+ * device_prefix is the prefix ("tape")
+ * device_node is what follows the prefix ("/dev/nst0")
+ *
+ * The caller retains responsibility to free or otherwise handle
+ * the passed strings.
+ */
+typedef Device* (*DeviceFactory)(char *device_name,
+ char * device_prefix,
+ char * device_node);
/* This function registers a new device with the allocation system.
* Call it after you register your type with the GLib type system.
- * This function takes ownership of the strings inside device_prefix_list,
- * but not the device_prefix_list itself. */
+ * This function assumes that the strings in device_prefix_list are
+ * statically allocated. */
extern void register_device(DeviceFactory factory,
const char ** device_prefix_list);
-/* This structure is a Flags (bitwise OR of values). Zero indicates success;
- * any other value indicates some kind of problem reading the label. If
- * multiple bits are set, it does not necessarily indicate that /all/ of
- * the specified issues occured, but rather that /at least one/ did. */
-typedef enum {
- /* When changing, Also update read_label_status_flags_values in device.c */
- READ_LABEL_STATUS_SUCCESS = 0,
- READ_LABEL_STATUS_DEVICE_MISSING = (1 << 0),
- READ_LABEL_STATUS_DEVICE_ERROR = (1 << 1),
- READ_LABEL_STATUS_VOLUME_MISSING = (1 << 2),
- READ_LABEL_STATUS_VOLUME_UNLABELED = (1 << 3),
- READ_LABEL_STATUS_VOLUME_ERROR = (1 << 4),
- READ_LABEL_STATUS_FLAGS_MAX = (1 << 5)
-} ReadLabelStatusFlags;
-
-#define READ_LABEL_STATUS_FLAGS_MASK (READ_LABEL_STATUS_MAX-1)
-#define READ_LABEL_STATUS_FLAGS_TYPE (read_label_status_flags_get_type())
-GType read_label_status_flags_get_type(void);
-
/*
* Class definition
*/
typedef struct _DeviceClass DeviceClass;
struct _DeviceClass {
GObjectClass __parent__;
- gboolean (* open_device) (Device * self,
- char * device_name); /* protected */
- ReadLabelStatusFlags (* read_label)(Device * self);
+ void (* open_device) (Device * self, char * device_name,
+ char * device_prefix, char * device_node);
+ gboolean (* configure) (Device * self, gboolean use_global_config);
+ DeviceStatusFlags (* read_label)(Device * self);
gboolean (* start) (Device * self, DeviceAccessMode mode,
char * label, char * timestamp);
- gboolean (* start_file) (Device * self, const dumpfile_t * info);
- gboolean (* write_block) (Device * self, guint size, gpointer data,
- gboolean last_block);
- gboolean (* write_from_fd) (Device * self, int fd);
+ gboolean (* start_file) (Device * self, dumpfile_t * info);
+ gboolean (* write_block) (Device * self, guint size, gpointer data);
+ gboolean (* write_from_fd) (Device * self, queue_fd_t *queue_fd);
gboolean (* finish_file) (Device * self);
dumpfile_t* (* seek_file) (Device * self, guint file);
gboolean (* seek_block) (Device * self, guint64 block);
int (* read_block) (Device * self, gpointer buf, int * size);
- gboolean (* read_to_fd) (Device * self, int fd);
- gboolean (* property_get) (Device * self, DevicePropertyId id,
- GValue * val);
- gboolean (* property_set) (Device * self, DevicePropertyId id,
- GValue * val);
+ gboolean (* read_to_fd) (Device * self, queue_fd_t *queue_fd);
+ gboolean (* property_get_ex) (Device * self, DevicePropertyId id,
+ GValue * val,
+ PropertySurety *surety,
+ PropertySource *source);
+ gboolean (* property_set_ex) (Device * self,
+ DevicePropertyId id,
+ GValue * val,
+ PropertySurety surety,
+ PropertySource source);
gboolean (* recycle_file) (Device * self, guint filenum);
gboolean (* finish) (Device * self);
+
+ /* array of DeviceProperty objects for this class, keyed by ID */
+ GArray *class_properties;
+
+ /* The return value of device_property_get_list */
+ GSList * class_properties_list;
};
+/*
+ * Device Instantiation
+ */
+
+/* This is how you get a new Device. Pass in a device name or alias.
+ *
+ * A Device is *always* returned, even for an invalid device name. You
+ * must check the resulting device->status to know if the device is valid
+ * to be used. If device->status is not DEVICE_STATUS_SUCCESS, then there
+ * was an error opening the device.
+ *
+ * Note that the Amanda configuration must be initialized, as this function
+ * looks for device definitions and other configuration information.
+ */
+Device* device_open (char * device_name);
+
+/* Once you have a new device, you should configure it. This sets properties
+ * on the device based on the user's configuation. If USE_GLOBAL_CONFIG is
+ * true, then any global device_property parameters are processed, along with
+ * tapetype and othe relevant parameters.
+ */
+gboolean device_configure(Device *self, gboolean use_global_config);
/*
- * Public methods
+ * Error Handling
+ */
+
+/* return the error message or the string "Unknown Device error". The
+ * string remains the responsibility of the Device, and should not
+ * be freed by the caller. */
+char *device_error(Device * self);
+
+/* return a string version of the status. The string remains the
+ * responsibility of the Device, and should not be freed by the
+ * caller. */
+char *device_status_error(Device * self);
+
+/* Return errmsg if it is set or a string version of the status. The
+ * string remains the responsibility of the Device, and should not
+ * be freed by the caller. */
+char *device_error_or_status(Device * self);
+
+/* Set the error message for this device; for use internally to the
+ * API. The string becomes the responsibility of the Device. If
+ * ERRMSG is NULL, the message is cleared. Note that the given flags
+ * are OR'd with any existing status flags. */
+void device_set_error(Device * self, char *errmsg, DeviceStatusFlags new_flags);
+
+/* Mostly for internal use, this is a boolean check to see whether a given
+ * device is in an error state. If this is TRUE, most operations on the
+ * device will fail.
*
- * Note to implementors: The default implementation of many of these
- * methods does not follow the documentation. For example, the default
- * implementation of device_read_block will always return -1, but
- * nonetheless update the block index in the Device structure. In
- * general, it is OK to chain up to the default implmentation after
- * successfully implementing whatever appears below. The particulars
- * of what the default implementations do is documented in device.c.
+ * The check is for DEVICE_STATUS_DEVICE_ERROR *alone*; if any other bits
+ * (e.g., VOLUME_UNLABELED) are set, then the device may not actually be in
+ * an error state.
*/
-GType device_get_type (void);
+#define device_in_error(dev) \
+ ((DEVICE(dev))->status == DEVICE_STATUS_DEVICE_ERROR)
-/* This is how you get a new Device. Pass in a device name like
- * file:/path/to/storage, and (assuming everything goes OK) you will get
- * back a nice happy Device* that you can do operations on. Note that you
- * must device_start() it before you can do anything besides talk about
- * properties or read the label. device_name remains the responsibility
- * of the caller. */
-Device* device_open (char * device_name);
+/*
+ * Public methods
+ */
-/* This instructs the device to read the label on the current
- * volume. device->volume_label will not be initalized until after this
- * is called. You are encouraged to read the label only after setting any
- * properties that may affect the label-reading process. */
-ReadLabelStatusFlags device_read_label (Device * self);
+/* This instructs the device to read the label on the current volume.
+ * device->volume_label will not be initalized until read_label or start is
+ * called. You are encouraged to read the label only after setting any
+ * properties that may affect the label-reading process. Also, after
+ * calling this function, device->volume_label and device->volume_time
+ * will be non-NULL if and only if this function returns
+ * DEVICE_STATUS_SUCCESS. */
+DeviceStatusFlags device_read_label (Device * self);
/* This tells the Device that it's OK to start reading and writing
* data. Before you call this, you can only call
* You should pass a label and timestamp if and only if you are
* opening in WRITE mode (not READ or APPEND). The label and timestamp
* remain the caller's responsibility in terms of memory management. The
- * passed timestamp may be NULL, in which case it will be filled in with
- * the current time. */
+ * passed timestamp may be NULL, in which case it will be filled in with
+ * the current time.
+ *
+ * Note that implementations need not calculate a the current time: the
+ * dispatch function does it for you. */
gboolean device_start (Device * self,
DeviceAccessMode mode, char * label,
char * timestamp);
/* This undoes device_start, returning you to the NULL state. Do this
* if you want to (for example) change access mode.
- *
+ *
* Note to subclass implementors: Call this function first from your
* finalization function. */
gboolean device_finish (Device * self);
-/* But you can't write any data until you call this function, too.
- * This function does not take ownership of the passed dumpfile_t; you must
- * free it yourself. */
+/* But you can't write any data until you call this function, too. This
+ * function does not take ownership of the passed dumpfile_t; you must free it
+ * yourself. Note that this function *does* set the blocksize field of the
+ * header properly, based on the size of the header block. */
gboolean device_start_file (Device * self,
- const dumpfile_t * jobInfo);
-
-guint device_write_min_size (Device * self);
-guint device_write_max_size (Device * self);
-guint device_read_max_size (Device * self);
+ dumpfile_t * jobInfo);
-/* Does what you expect. size had better be inside the block size
- * range, or this function will write nothing.
- *
- * The short_block parameter needs some additional explanation: If
- * short_block is set to TRUE, then this function will accept a write
- * smaller than the minimum block size, subject to the following
- * caveats:
- * % The block may be padded with NULL bytes, which will be present on
- * restore.
- * % device_write_block will automatically call device_finish_file()
- * after writing this short block.
- * It is permitted to use short_block with a block that is not short;
- * in this case, it is equivalent to calling device_write() and then
- * calling device_finish_file(). */
+/* Does what you expect. Size must be device->block_size or less.
+ * If less, then this is the final block in the file, and no more blocks
+ * may be written until finish_file and start_file have been called. */
gboolean device_write_block (Device * self,
guint size,
- gpointer data,
- gboolean short_block);
+ gpointer data);
/* This will drain the given fd (reading until EOF), and write the
- * resulting data out to the device using maximally-sized blocks. */
+ * resulting data out to the device using maximally-sized blocks.
+ * This function does not call device_finish_file automatically.
+ */
gboolean device_write_from_fd (Device * self,
- int fd);
+ queue_fd_t *queue_fd);
-/* Call this when you are finished writing a file. This function will
- * write a filemark or the local equivalent, flush the buffers, and do
- * whatever dirty work needs to be done at such a point in time. */
+/* Call this when you are finished writing a file.
+ * This function will write a filemark or the local
+ * equivalent, flush the buffers, and do whatever dirty work needs
+ * to be done at such a point in time. */
gboolean device_finish_file (Device * self);
/* For reading only: Seeks to the beginning of a particular
* ACCESS_WRITE will start you out at the first file, and opening in
* ACCESS_APPEND will automatically seek to the end of the medium.
*
- * If the requested file doesn't exist, this function will seek to the
- * next-numbered valid file. You can check where this function seeked to
- * by examining the file field of the Device structure. If the requested
- * file number is exactly one more than the last valid file, this
+ * If the requested file doesn't exist, as might happen when a volume has
+ * had files recycled, then this function will seek to the next file that
+ * does exist. You can check which file this function selected by
+ * examining the file field of the Device structure. If the requested
+ * file number is *exactly* one more than the last valid file, this
* function returns a TAPEEND header.
*
* If an error occurs or if the requested file is two or more beyond the
* no read is performed, the function returns 0, and *size is set
* to the minimum buffer size required to read the next block. If an
* error occurs, the function returns -1 and *size is left unchanged.
- *
- * It is not an error if buffer == NULL and *size == 0. This should be
- * treated as a query as to the possible size of the next block. */
-int device_read_block (Device * self,
- gpointer buffer,
- int * size);
+ *
+ * Note that this function may request a block size bigger than
+ * dev->block_size, if it discovers an oversized block. This allows Amanda to
+ * read from volumes regardless of the block size used to write them. It is not
+ * an error if buffer == NULL and *size == 0. This should be treated as a query
+ * as to the possible size of the next block, although it is not an error for
+ * the next read to request an even larger block size. */
+int device_read_block (Device * self, gpointer buffer, int * size);
/* This is the reading equivalent of device_write_from_fd(). It will
* read from the device from the current location until end of file,
* and drains the results out into the specified fd. Returns FALSE if
* there is a problem writing to the fd. */
gboolean device_read_to_fd (Device * self,
- int fd);
+ queue_fd_t *queue_fd);
-/* This function tells you what properties are supported by this
- * device, and when you are allowed to get and set them. The return
- * value is an array of DeviceProperty structs. The last struct in
- * the array is zeroed, so you know when the end is (check the
- * pointer element "base"). The return value from this function on any
- * given object (or physical device) should be invariant. */
-const DeviceProperty * device_property_get_list (Device * self);
+/* This function tells you what properties are supported by this device, and
+ * when you are allowed to get and set them. The return value is an list of
+ * DeviceProperty structs. Do not free the resulting list. */
+const GSList * device_property_get_list (Device * self);
/* These functions get or set a particular property. The val should be
* compatible with the DevicePropertyBase associated with the given
- * DevicePropertyId, and this function should only be called when
- * DeviceProperty.access says it is OK. Otherwise you will get an
- * error and not the tasty property action you wanted. */
-gboolean device_property_get (Device * self,
+ * DevicePropertyId, and these functions should only be called when
+ * DeviceProperty.access says it is OK. Otherwise you will get an error and not
+ * the tasty property action you wanted.
+ *
+ * All device_property_get_ex parameters but the first two are output
+ * parameters, and can be left NULL if you are not interested in their value.
+ * If you only need the value, use the simpler device_property_get macro. */
+
+gboolean device_property_get_ex (Device * self,
DevicePropertyId id,
- GValue * val);
-gboolean device_property_set (Device * self,
+ GValue * val,
+ PropertySurety *surety,
+ PropertySource *source);
+#define device_property_get(self, id, val) \
+ device_property_get_ex((self), (id), (val), NULL, NULL)
+
+gboolean device_property_set_ex (Device * self,
DevicePropertyId id,
- GValue * val);
+ GValue * val,
+ PropertySurety surety,
+ PropertySource source);
+#define device_property_set(self, id, val) \
+ device_property_set_ex((self), (id), (val), \
+ PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_USER)
/* On devices that support it (check PROPERTY_PARTIAL_DELETION),
* this will free only the space associated with a particular file.
/* Protected methods. Don't call these except in subclass implementations. */
-/* Registers a new device / property pair. Every superclass of Device
- * should call this in its init() function. At the moment, any
- * particular property Id can only be registered once per object.
- *
- * If you want to register a standard response to a property (e.g.,
- * whether or not the device supports compression), you can pass a
- * non-NULL response. Then the default implementation of
- * device_get_property (which you may override) will return this
- * response.
- * The contents of prop and response are copied into a private array, so the
- * calling function retains ownership of all arguments.
- */
-void device_add_property(Device * self, DeviceProperty * prop,
- GValue * response);
-
/* This method provides post-construction initalization once the
* device name is known. It should only be used by Device
* factories. It is provided here as a virtual method (instead of
* a static function) because some devices may want to chain
* initilization to their parents. */
-gboolean device_open_device (Device * self,
- char * device_name);
+void device_open_device (Device * self, char *device_name, char *device_type, char *device_node);
/* Builds a proper header based on device block size possibilities.
* If non-null, size is filled in with the number of bytes that should
/* Does what you expect. Uses the current time. */
dumpfile_t * make_tapeend_header(void);
-/* Set up first-run properties from loaded configuration file, including
- * DEVICE_MAX_VOLUME_USAGE property based on the tapetype. */
-void device_set_startup_properties_from_config(Device * device);
-
/* Erase any stored volume information. Use this if something happens (e.g.,
* a property is set) that voids previously-read volume details.
* This function is a NOOP unless the device is in the NULL state. */
void device_clear_volume_details(Device * device);
+/* Property Handling */
+
+/* Registers a property for a new device class; device drivers' GClassInitFunc
+ * should call this function for each device-specific property of the class.
+ * If either getter or setter is NULL, then the corresponding operation will
+ * return FALSE.
+ *
+ * Note that this will replace any existing registration (e.g., from a parent
+ * class).
+ */
+void device_class_register_property(DeviceClass *klass, DevicePropertyId id,
+ PropertyAccessFlags access,
+ PropertyGetFn getter,
+ PropertySetFn setter);
+
+/* Set a 'simple' property on the device. This tucks the value away in the
+ * object, to be retrieved by device_simple_property_get_fn. This is most
+ * often used in GInstanceInit functions, but can be used at any time to set or
+ * change the value of a simple property */
+gboolean device_set_simple_property(Device *self, DevicePropertyId id,
+ GValue *val, PropertySurety surety,
+ PropertySource source);
+
+/* Get a simple property set with device_set_simple_property. This is a little
+ * bit quicker than calling device_property_get_ex(), and does not affect the
+ * device's error state. Returns FALSE if the property has not been set.
+ * Surety and source are output parameters and will be ignored if they are
+ * NULL. */
+gboolean device_get_simple_property(Device *self, DevicePropertyId id,
+ GValue *val, PropertySurety *surety,
+ PropertySource *source);
+
+/* A useful PropertySetFn. If your subclass also needs to intercept sets, for
+ * example to flush a cache or update a member variable, then write a stub
+ * function which "calls up" to this function. */
+gboolean device_simple_property_set_fn(Device *self, DevicePropertyBase *base,
+ GValue *val, PropertySurety surety,
+ PropertySource source);
+
+/* A useful PropertyGetFn -- returns the value, source, and surety set with
+ * device_set_simple_property */
+gboolean device_simple_property_get_fn(Device *self, DevicePropertyBase *base,
+ GValue *val, PropertySurety *surety,
+ PropertySource *source);
+
#endif /* DEVICE_H */
projects / debian / amanda / blobdiff