X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=osl.h.in;h=2abe135d7967446643aa6a803656aaa85b754d14;hb=HEAD;hp=20e930ffae7b567c13ea72975ba1a636e589a290;hpb=1106c6859585063b4ecca34e8fec7d0f3c65ef40;p=osl.git diff --git a/osl.h.in b/osl.h.in deleted file mode 100644 index 20e930f..0000000 --- a/osl.h.in +++ /dev/null @@ -1,504 +0,0 @@ -/* - * Copyright (C) 2007-2008 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ - -/** \file osl.h User interface for the object storage layer. */ - -#include - -/** Export all declarations in this file. */ -#pragma GCC visibility push(default) - -/** Describes an object of the object storage layer (osl) */ -struct osl_object { - /** Pointer to the data of the object. */ - void *data; - /** The object's size. */ - size_t size; -}; - -/** Flags that change the internal handling of osl tables. */ -enum osl_table_flags { - /** This table will have many rows. */ - OSL_LARGE_TABLE = 1 -}; - -/** The three different types of storage for an osl column */ -enum osl_storage_type { - /** - * All data for this column is stored in one file which gets mmapped by - * osl_open_table(). This is suitable for columns that do not hold much - * data. - */ - OSL_MAPPED_STORAGE, - /** - * Each entry is stored on disk and is loaded on demand by - * open_disk_object(). This is the preferable storage type for large - * objects that need not be in memory all the time. - */ - OSL_DISK_STORAGE, - /** - * Objects for columns of this type are volatile: They are only stored - * in memory and are discarded once the table gets closed. - */ - OSL_NO_STORAGE -}; - -/** - * Additional per-column flags - */ -enum osl_storage_flags { - /** - * Build an rbtree for this column. This is only possible if the - * storage type of the column is either \a OSL_MAPPED_STORAGE or \a - * OSL_NO_STORAGE. In order to lookup objects in the table by using \a - * osl_get_row(), the lookup column must have an associated rbtree. - * - * \sa osl_storage_type, osl_get_row() - */ - OSL_RBTREE = 1, - /** The data for this column will have constant size. */ - OSL_FIXED_SIZE = 2, - /** All values of this column will be different. */ - OSL_UNIQUE = 4, - /** Do not free the data for this column (\p OSL_NO_STORAGE). */ - OSL_DONT_FREE = 8 -}; - -/** Opaque osl table structure. */ -struct osl_table; -/** Opaque osl row structure. */ -struct osl_row; - -/** - * In order to build up an rbtree a compare function for the objects must be - * specified. Such a function always takes pointers to the two objects to be - * compared. It must return -1, zero, or 1, if the first argument is considered - * to be respectively less than, equal to, or greater than the second. If two - * members compare as equal, their order in the sorted array is undefined. - */ -typedef int osl_compare_func(const struct osl_object *obj1, - const struct osl_object *obj2); - -/** - * The osl_rbreee_loop functions take a function pointer of this type. For each - * node in the rbtree, the given function is called. - * - * \sa osl_rbtree_loop(), osl_rbtree_loop_reverse(). - */ -typedef int osl_rbtree_loop_func(struct osl_row *row, void *data); - -/** - * Describes one column of a osl table. - */ -struct osl_column_description { - /** One of the tree possible types of storage */ - enum osl_storage_type storage_type; - /** Specifies further properties of the column */ - enum osl_storage_flags storage_flags; - /** - * The column name determines the name of the directory where all data - * for this column will be stored. Its hash is stored in the table - * header. This field is ignored if the storage type is \a NO_STORAGE - */ - char *name; - /** - * For columns with an associated rbtree, this must point to a function - * that compares the values of two objects, either a built-in function - * or a function defined by the application may be supplied. This - * field is ignored if the column does not have an associated rbtree. - * - * \sa osl_storage_flags, osl_compare_func - */ - osl_compare_func *compare_function; - /** - * If the \a OSL_FIXED_SIZE flag is set for this column, this value - * determines the fixed size of all objects of this column. It is - * ignored, if \a OSL_FIXED_SIZE is not set. - */ - uint32_t data_size; -}; - -/** - * Describes one osl table. - */ -struct osl_table_description { - /** The directory which contains all files of this table. */ - const char *dir; - /** - * The table name. A subdirectory of \a dir called \a name is created - * at table creation time. It must be a valid name for a subdirectory. - * In particular, no slashes are allowed for \a name. - */ - const char *name; - /** The number of columns of this table. */ - uint16_t num_columns; - /** Further table-wide information. */ - enum osl_table_flags flags; - /** The array describing the individual columns of the table. */ - struct osl_column_description *column_descriptions; -}; - -/** Flags to be passed to \a osl_close_table(). */ -enum osl_close_flags { - /** - * The table header contains a "dirty" flag which specifies whether - * the table is currently open by another process. This flag specifies - * that the dirty flag should be cleared before closing the table. - */ - OSL_MARK_CLEAN = 1, - /** - * If the table contains columns of type \a OSL_NO_STORAGE and this - * flag is passed to osl_close_table(), free(3) is called for each - * object of each column of type \a OSL_NO_STORAGE. - */ - OSL_FREE_VOLATILE = 2 -}; - -/** - * Create a new osl table. - * - * \param desc Pointer to the table description. - * - * \return Standard. - */ -int osl_create_table(const struct osl_table_description *desc); - -/** - * Open an osl table. - * - * Each osl table must be opened before its data can be accessed. - * - * \param table_desc Describes the table to be opened. - * \param result Contains a pointer to the open table on success. - * - * The table description given by \a desc should coincide with the - * description used at creation time. - * - * \return Standard. - */ -int osl_open_table(const struct osl_table_description *desc, - struct osl_table **result); - -/** - * Close an osl table. - * - * \param t Pointer to the table to be closed. - * \param flags Options for what should be cleaned up. - * - * If osl_open_table() succeeds, the resulting table pointer must later be - * passed to this function in order to flush all changes to the file system and - * to free the resources that were allocated by osl_open_table(). - * - * \return Standard. - * - * \sa osl_open_table(), unmap_table(). - */ -int osl_close_table(struct osl_table *t, enum osl_close_flags flags); - -/** - * Get the row that contains the given object. - * - * \param t Pointer to an open osl table. - * \param col_num The number of the column to be searched. - * \param obj The object to be looked up. - * \param result Points to the row containing \a obj. - * - * Lookup \a obj in \a t and return the row containing \a obj. The column - * specified by \a col_num must have an associated rbtree. - * - * \return Standard. - * - * \sa osl_storage_flags - */ -int osl_get_row(const struct osl_table *t, unsigned col_num, - const struct osl_object *obj, struct osl_row **result); - -/** - * Retrieve an object identified by row and column - * - * \param t Pointer to an open osl table. - * \param r Pointer to the row. - * \param col_num The column number. - * \param object The result pointer. - * - * The column determined by \a col_num must be of type \p OSL_MAPPED_STORAGE - * or \p OSL_NO_STORAGE, i.e. no disk storage objects may be retrieved by this - * function. - * - * \return Standard. - * - * \sa osl_storage_type, osl_open_disk_object(). - */ -int osl_get_object(const struct osl_table *t, const struct osl_row *row, - unsigned col_num, struct osl_object *object); - -/** - * Retrieve an object of type \p OSL_DISK_STORAGE by row and column. - * - * \param t Pointer to an open osl table. - * \param r Pointer to the row containing the object. - * \param col_num The column number. - * \param obj Points to the result upon successful return. - * - * For columns of type \p OSL_DISK_STORAGE, this function must be used to - * retrieve one of its containing objects. Afterwards, osl_close_disk_object() - * must be called in order to deallocate the resources. - * - * \return Standard. - * - * \sa osl_get_object(), osl_storage_type, osl_close_disk_object(). - */ -int osl_open_disk_object(const struct osl_table *t, - const struct osl_row *r, unsigned col_num, struct osl_object *obj); - -/** - * Free resources that were allocated during osl_open_disk_object(). - * - * \param obj Pointer to the object previously returned by open_disk_object(). - * - * \return The return value of the underlying call to para_munmap(). - * - * \sa para_munmap(). - */ -int osl_close_disk_object(struct osl_object *obj); - -/** - * Add a new row to an osl table and retrieve this row. - * - * \param t Pointer to an open osl table. - * \param objects Array of objects to be added. - * \param row Result pointer. - * - * The \a objects parameter must point to an array containing one object per - * column. The order of the objects in the array is given by the table - * description of \a table. Several sanity checks are performed during object - * insertion and the function returns without modifying the table if any of - * these tests fail. In fact, it is atomic in the sense that it either - * succeeds or leaves the table unchanged (i.e. either all or none of the - * objects are added to the table). - * - * It is considered an error if an object is added to a column with associated - * rbtree if this object is equal to an object already contained in that column - * (i.e. the compare function for the column's rbtree returns zero). - * - * \return Standard. - * - * \sa struct osl_table_description, osl_compare_func, osl_add_row(). - */ -int osl_add_and_get_row(struct osl_table *t, struct osl_object *objects, - struct osl_row **row); - - -/** - * Add a new row to an osl table. - * - * \param t Same meaning as osl_add_and_get_row(). - * \param objects Same meaning as osl_add_and_get_row(). - * - * \return The return value of the underlying call to osl_add_and_get_row(). - * - * This is equivalent to osl_add_and_get_row(t, objects, NULL). - */ -int osl_add_row(struct osl_table *t, struct osl_object *objects); - -/** - * Delete a row from an osl table. - * - * \param t Pointer to an open osl table. - * \param row Pointer to the row to delete. - * - * This removes all disk storage objects, removes all rbtree nodes, and frees - * all volatile objects belonging to the given row. For mapped columns, the - * data is merely marked invalid and may be pruned from time to time by - * para_fsck. - * - * \return Standard. - */ -int osl_del_row(struct osl_table *t, struct osl_row *row); - -/** - * Loop over all nodes in an rbtree. - * - * \param t Pointer to an open osl table. - * \param col_num The column to use for iterating over the elements. - * \param private_data Pointer that gets passed to \a func. - * \param func The function to be called for each node in the rbtree. - * - * This function does an in-order walk of the rbtree associated with \a - * col_num. It is an error if the \p OSL_RBTREE flag is not set for this - * column. For each node in the rbtree, the given function \a func is called - * with two pointers as arguments: The first osl_row* argument points to the - * row that contains the object corresponding to the rbtree node currently - * traversed, and the \a private_data pointer is passed verbatim to \a func as the - * second argument. The loop terminates either if \a func returns a negative - * value, or if all nodes of the tree have been visited. - * - * - * \return Standard. If the termination of the loop was caused by \a func - * returning a negative value, \p -E_OSL_LOOP is returned. - * - * \sa osl_storage_flags, osl_rbtree_loop_reverse(), osl_compare_func. - */ -int osl_rbtree_loop(const struct osl_table *t, unsigned col_num, - void *private_data, osl_rbtree_loop_func *func); - -/** - * Loop over all nodes in an rbtree in reverse order. - * - * \param t Identical meaning as in \p osl_rbtree_loop(). - * \param col_num Identical meaning as in \p osl_rbtree_loop(). - * \param private_data Identical meaning as in \p osl_rbtree_loop(). - * \param func Identical meaning as in \p osl_rbtree_loop(). - * - * This function is identical to \p osl_rbtree_loop(), the only difference - * is that the tree is walked in reverse order. - * - * \return The same return value as \p osl_rbtree_loop(). - * - * \sa osl_rbtree_loop(). - */ -int osl_rbtree_loop_reverse(const struct osl_table *t, unsigned col_num, - void *private_data, osl_rbtree_loop_func *func); - -/** - * Change an object in an osl table. - * - * \param t Pointer to an open osl table. - * \param r Pointer to the row containing the object to be updated. - * \param col_num Number of the column containing the object to be updated. - * \param obj Pointer to the replacement object. - * - * This function gets rid of all references to the old object. This includes - * removal of the rbtree node in case there is an rbtree associated with \a - * col_num. It then inserts \a obj into the table and the rbtree if necessary. - * - * If the \p OSL_RBTREE flag is set for \a col_num, you \b MUST call this - * function in order to change the contents of an object, even for volatile or - * mapped columns of constant size (which may be updated directly if \p - * OSL_RBTREE is not set). Otherwise the rbtree might become corrupted. - * - * \return Standard - */ -int osl_update_object(struct osl_table *t, const struct osl_row *r, - unsigned col_num, struct osl_object *obj); - -/** - * Get the number of rows of the given table. - * - * \param t Pointer to an open osl table. - * \param num_rows Result is returned here. - * - * The number of rows returned via \a num_rows excluding any invalid rows. - * - * \return Positive on success, \p -E_OSL_BAD_TABLE if \a t is \p NULL. - */ -int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows); - - -/** - * Get the row corresponding to the smallest rbtree node of a column. - * - * \param t An open rbtree table. - * \param col_num The number of the rbtree column. - * \param result A pointer to the first row is returned here. - * - * The rbtree node of the smallest object (with respect to the corresponding - * compare function) is selected and the row containing this object is - * returned. It is an error if \a col_num refers to a column without an - * associated rbtree. - * - * \return Standard. - * - * \sa osl_get_nth_row(), osl_rbtree_last_row(). - */ -int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num, - struct osl_row **result); - -/** - * Get the row corresponding to the greatest rbtree node of a column. - * - * \param t The same meaning as in \p osl_rbtree_first_row(). - * \param col_num The same meaning as in \p osl_rbtree_first_row(). - * \param result The same meaning as in \p osl_rbtree_first_row(). - * - * This function works just like osl_rbtree_first_row(), the only difference - * is that the row containing the greatest rather than the smallest object is - * returned. - * - * \return Standard. - * - * \sa osl_get_nth_row(), osl_rbtree_first_row(). - */ -int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num, - struct osl_row **result); - -/** - * Get the row with n-th greatest value. - * - * \param t Pointer to an open osl table. - * \param col_num The column number. - * \param n The rank of the desired row. - * \param result Row is returned here. - * - * Retrieve the n-th order statistic with respect to the compare function - * of the rbtree column \a col_num. In other words, get that row with - * \a n th greatest value in column \a col_num. It's an error if - * \a col_num is not a rbtree column, or if \a n is larger than the - * number of rows in the table. - * - * \return Standard. - * - * \sa osl_storage_flags, osl_compare_func, osl_get_row(), - * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank(). - */ -int osl_get_nth_row(const struct osl_table *t, unsigned col_num, - unsigned n, struct osl_row **result); - -/** - * Get the rank of a row. - * - * \param t An open osl table. - * \param r The row to get the rank of. - * \param col_num The number of an rbtree column. - * \param rank Result pointer. - * - * The rank is, by definition, the position of the row in the linear order - * determined by an in-order tree walk of the rbtree associated with column - * number \a col_num of \a table. - * - * \return Standard. - * - * \sa osl_get_nth_row(). - */ -int osl_get_rank(const struct osl_table *t, struct osl_row *r, - unsigned col_num, unsigned *rank); - -/** - * Compare two osl objects pointing to hash values. - * - * \param obj1 Pointer to the first hash object. - * \param obj2 Pointer to the second hash object. - * - * \return The values required for an osl compare function. - * - * \sa osl_compare_func, uint32_compare(). - */ -int osl_hash_compare(const struct osl_object *obj1, - const struct osl_object *obj2); - -/** - * Get a string describing the error code passed in the argument. - * - * \param num The error code. - * - * This works just like strerror(3). The given number must be an osl error - * code. The result must not be freed by the caller. - * - * \return The error text corresponding to an osl error code. - */ -const char *osl_strerror(int num); - -#pragma GCC visibility pop