![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
index 090b76bf0269bb0b59263478912e0b8cd454efa8..f0fc0c7d779cf4504eb67f316c6846c8f7e99303 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
/*
* SysDB - src/include/core/store.h
- * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * Copyright (C) 2012-2015 Sebastian 'tokkee' Harl <sh@tokkee.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
#include "parser/ast.h"
#include "utils/strbuf.h"
-#include <stdbool.h>
#include <stdio.h>
#ifdef __cplusplus
: -1)
/*
- * sdb_store_t represents an in-memory store. It inherits from sdb_object_t
- * and may safely be case to a generic object.
+ * sdb_store_host_t represents the meta-data of a stored host object.
*/
-struct sdb_store;
-typedef struct sdb_store sdb_store_t;
-#define SDB_STORE(obj) ((sdb_store_t *)(obj))
+typedef struct {
+ const char *name;
+
+ sdb_time_t last_update;
+ sdb_time_t interval;
+ const char * const *backends;
+ size_t backends_num;
+} sdb_store_host_t;
+#define SDB_STORE_HOST_INIT { NULL, 0, 0, NULL, 0 }
/*
- * sdb_store_obj_t represents the super-class of any object stored in the
- * database. It inherits from sdb_object_t and may safely be cast to a generic
- * object to access its name.
+ * sdb_store_service_t represents the meta-data of a stored service object.
*/
-struct sdb_store_obj;
-typedef struct sdb_store_obj sdb_store_obj_t;
+typedef struct {
+ const char *hostname;
+ const char *name;
+
+ sdb_time_t last_update;
+ sdb_time_t interval;
+ const char * const *backends;
+ size_t backends_num;
+} sdb_store_service_t;
+#define SDB_STORE_SERVICE_INIT { NULL, NULL, 0, 0, NULL, 0 }
/*
- * A metric store describes how to access a metric's data.
+ * sdb_metric_store_t specifies how to access a metric's data.
*/
typedef struct {
const char *type;
const char *id;
+ const sdb_timeseries_info_t *info;
+ sdb_time_t last_update;
} sdb_metric_store_t;
/*
- * Expressions represent arithmetic expressions based on stored objects and
- * their various attributes.
- *
- * An expression object inherits from sdb_object_t and, thus, may safely be
- * cast to a generic object.
+ * sdb_store_metric_t represents the meta-data of a stored metric object.
*/
-struct sdb_store_expr;
-typedef struct sdb_store_expr sdb_store_expr_t;
-#define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
+typedef struct {
+ const char *hostname;
+ const char *name;
-/*
- * An expression iterator iterates over the values of an iterable expression.
- */
-struct sdb_store_expr_iter;
-typedef struct sdb_store_expr_iter sdb_store_expr_iter_t;
+ /* All data stores providing this metric. */
+ const sdb_metric_store_t *stores;
+ size_t stores_num;
+
+ sdb_time_t last_update;
+ sdb_time_t interval;
+ const char * const *backends;
+ size_t backends_num;
+} sdb_store_metric_t;
+#define SDB_STORE_METRIC_INIT { NULL, NULL, NULL, 0, 0, 0, NULL, 0 }
/*
- * Store matchers may be used to lookup hosts from the store based on their
- * various attributes. Service and attribute matchers are applied to a host's
- * services and attributes and evaluate to true if *any* service or attribute
- * matches.
- *
- * A store matcher object inherits from sdb_object_t and, thus, may safely be
- * cast to a generic object.
+ * sdb_store_attribute_t represents a stored attribute.
*/
-struct sdb_store_matcher;
-typedef struct sdb_store_matcher sdb_store_matcher_t;
-#define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
+typedef struct {
+ const char *hostname; /* optional */
+ int parent_type;
+ const char *parent;
+ const char *key;
+ sdb_data_t value;
+
+ sdb_time_t last_update;
+ sdb_time_t interval;
+ const char * const *backends;
+ size_t backends_num;
+} sdb_store_attribute_t;
+#define SDB_STORE_ATTRIBUTE_INIT { NULL, 0, NULL, NULL, SDB_DATA_INIT, 0, 0, NULL, 0 }
/*
* A JSON formatter converts stored objects into the JSON format.
* specified name and timestamp. Else, a new entry will be created in the
* store.
*/
- int (*store_host)(const char *name, sdb_time_t last_update,
- sdb_object_t *user_data);
+ int (*store_host)(sdb_store_host_t *host, sdb_object_t *user_data);
/*
* store_service:
* does not exist, an error will be reported. Else, a new entry will be
* created in the store.
*/
- int (*store_service)(const char *hostname, const char *name,
- sdb_time_t last_update, sdb_object_t *user_data);
+ int (*store_service)(sdb_store_service_t *service, sdb_object_t *user_data);
/*
* store_metric:
* exist, an error will be reported. Else, a new entry will be created in
* the store.
*/
- int (*store_metric)(const char *hostname, const char *name,
- sdb_metric_store_t *store, sdb_time_t last_update,
- sdb_object_t *user_data);
+ int (*store_metric)(sdb_store_metric_t *metric, sdb_object_t *user_data);
/*
* store_attribute:
* exist, an error will be reported. Else, a new entry will be created in
* the store.
*/
- int (*store_attribute)(const char *hostname,
- const char *key, const sdb_data_t *value, sdb_time_t last_update,
- sdb_object_t *user_data);
-
- /*
- * store_service_attr:
- * Add/update a service's attribute in the store. If the attribute,
- * identified by its key, already exists for the specified service, it
- * will be updated to the specified value. If the references service (for
- * the specified host) does not exist, an error will be reported.
- */
- int (*store_service_attr)(const char *hostname, const char *service,
- const char *key, const sdb_data_t *value, sdb_time_t last_update,
- sdb_object_t *user_data);
-
- /*
- * store_metric_attr:
- * Add/update a metric's attribute in the store. If the attribute,
- * identified by its key, already exists for the specified metric, it will
- * be updated to the specified value. If the references metric (for the
- * specified host) does not exist, an error will be reported.
- */
- int (*store_metric_attr)(const char *hostname, const char *metric,
- const char *key, const sdb_data_t *value, sdb_time_t last_update,
- sdb_object_t *user_data);
+ int (*store_attribute)(sdb_store_attribute_t *attr, sdb_object_t *user_data);
} sdb_store_writer_t;
-/*
- * sdb_store_writer:
- * A store writer implementation that provides an in-memory object store. It
- * expects a store object as its user-data argument.
- */
-extern sdb_store_writer_t sdb_store_writer;
-
/*
* A store reader describes the interface to query a store implementation.
*/
* execute_query:
* Execute a previously prepared query. The callback may expect that only
* queries prepared by its respective prepare callback will be passed to
- * this function.
- *
- * TODO: Instead of letting the executor write directly to a string buffer
- * (which cannot easily be merged with other results), let it hand
- * all objects to a store-writer.
+ * this function. The query result will be passed back via the specified
+ * store writer.
*/
int (*execute_query)(sdb_object_t *q,
- sdb_strbuf_t *buf, sdb_strbuf_t *errbuf,
- sdb_object_t *user_data);
+ sdb_store_writer_t *w, sdb_object_t *wd,
+ sdb_strbuf_t *errbuf, sdb_object_t *user_data);
} sdb_store_reader_t;
-/*
- * sdb_store_reader:
- * A store reader implementation that uses an in-memory object store. It
- * expects a store object as its user-data argument.
- */
-extern sdb_store_reader_t sdb_store_reader;
-
-/*
- * sdb_store_create:
- * Allocate a new in-memory store.
- */
-sdb_store_t *
-sdb_store_create(void);
-
-/*
- * sdb_store_host, sdb_store_service, sdb_store_metric, sdb_store_attribute,
- * sdb_store_metric_attr:
- * Store an object in the specified store. The hostname is expected to be
- * canonical.
- */
-int
-sdb_store_host(sdb_store_t *store, const char *name, sdb_time_t last_update);
-int
-sdb_store_service(sdb_store_t *store, const char *hostname, const char *name,
- sdb_time_t last_update);
-int
-sdb_store_metric(sdb_store_t *store, const char *hostname, const char *name,
- sdb_metric_store_t *metric_store, sdb_time_t last_update);
-int
-sdb_store_attribute(sdb_store_t *store, const char *hostname,
- const char *key, const sdb_data_t *value, sdb_time_t last_update);
-int
-sdb_store_service_attr(sdb_store_t *store, const char *hostname,
- const char *service, const char *key, const sdb_data_t *value,
- sdb_time_t last_update);
-int
-sdb_store_metric_attr(sdb_store_t *store, const char *hostname,
- const char *metric, const char *key, const sdb_data_t *value,
- sdb_time_t last_update);
-
-/*
- * sdb_store_get_host:
- * Query the specified store for a host by its (canonicalized) name.
- *
- * The function increments the ref count of the host object. The caller needs
- * to deref it when no longer using it.
- */
-sdb_store_obj_t *
-sdb_store_get_host(sdb_store_t *store, const char *name);
-
-/*
- * sdb_store_fetch_timeseries:
- * Fetch the time-series described by the specified host's metric and
- * serialize it as JSON into the provided string buffer. The host data is
- * retrieved from the specified store.
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_fetch_timeseries(sdb_store_t *store,
- const char *hostname, const char *metric,
- sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
-
-/*
- * sdb_store_get_child:
- * Retrieve a host's child object of the specified type and name. The
- * reference count of the child object will be incremented before returning
- * it. The caller is responsible for releasing the object once it's no longer
- * used.
- *
- * Returns:
- * - the child object on success
- * - NULL else
- */
-sdb_store_obj_t *
-sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name);
-
-/*
- * sdb_store_get_field:
- * Get the value of a stored object's queryable field. The caller is
- * responsible for freeing any dynamically allocated memory possibly stored in
- * the returned value. If 'res' is NULL, the function will return whether the
- * field exists.
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
-
-/*
- * sdb_store_get_attr:
- * Get the value of a stored object's attribute. The caller is responsible for
- * freeing any dynamically allocated memory possibly stored in the returned
- * value. If 'res' is NULL, the function will return whether the attribute
- * exists. If specified, only attributes matching the filter will be
- * considered.
- *
- * Returns:
- * - 0 if the attribute exists
- * - a negative value else
- */
-int
-sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
- sdb_store_matcher_t *filter);
-
-/*
- * Querying a store:
- *
- * - Query interface: A query is a formal description of an interaction with
- * the store. It can be used, both, for read and write access. The query is
- * described by its abstract syntax tree (AST). The parser package provides
- * means to parse a string (SysQL) representation of the query into an AST.
- *
- * - Matcher / expression interface: This low-level interface provides direct
- * control over how to access the store. It is used by the query
- * implementation internally and can only be used for read access.
- */
-
-/*
- * sdb_store_query_t:
- * A parsed query readily prepared for execution.
- */
-struct sdb_store_query;
-typedef struct sdb_store_query sdb_store_query_t;
-
-/*
- * sdb_store_query_prepare:
- * Prepare the query described by 'ast' for execution in a store.
- *
- * Returns:
- * - a store query on success
- * - NULL else
- */
-sdb_store_query_t *
-sdb_store_query_prepare(sdb_ast_node_t *ast);
-
-/*
- * sdb_store_query_prepare_matcher:
- * Prepare the logical expression described by 'ast' for execution as a store
- * matcher.
- *
- * Returns:
- * - a matcher on success
- * - NULL else
- */
-sdb_store_matcher_t *
-sdb_store_query_prepare_matcher(sdb_ast_node_t *ast);
-
-/*
- * sdb_store_query_execute:
- * Execute a previously prepared query in the specified store. The query
- * result will be written to 'buf' and any errors to 'errbuf'.
- *
- * Returns:
- * - the result type (to be used by the server reply)
- * - a negative value on error
- */
-int
-sdb_store_query_execute(sdb_store_t *store, sdb_store_query_t *m,
- sdb_strbuf_t *buf, sdb_strbuf_t *errbuf);
-
-/*
- * sdb_store_expr_create:
- * Creates an arithmetic expression implementing the specified operator on the
- * specified left and right operand.
- *
- * Returns:
- * - an expression object on success
- * - NULL else
- */
-sdb_store_expr_t *
-sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
-
-/*
- * sdb_store_expr_typed:
- * Creates an expression which evaluates in the context of an object's sibling
- * as specified by the given type.
- *
- * Returns:
- * - an expression object on success
- * - NULL else
- */
-sdb_store_expr_t *
-sdb_store_expr_typed(int typ, sdb_store_expr_t *expr);
-
-/*
- * sdb_store_expr_fieldvalue:
- * Creates an expression which evaluates to the value of the specified
- * queryable field of a stored object.
- *
- * Returns:
- * - an expression object on success
- * - NULL else
- */
-sdb_store_expr_t *
-sdb_store_expr_fieldvalue(int field);
-
-/*
- * sdb_store_expr_attrvalue:
- * Creates an expression which evaluates to the value of the specified
- * attribute of a stored object. Evaluates to a NULL value if the attribute
- * does not exist.
- *
- * Returns:
- * - an expression object on success
- * - NULL else
- */
-sdb_store_expr_t *
-sdb_store_expr_attrvalue(const char *name);
-
-/*
- * sdb_store_expr_constvalue:
- * Creates an expression which evaluates to the specified constant value.
- *
- * Returns:
- * - an expression object on success
- * - NULL else
- */
-sdb_store_expr_t *
-sdb_store_expr_constvalue(const sdb_data_t *value);
-
-/*
- * sdb_store_expr_eval:
- * Evaluate an expression for the specified stored object and stores the
- * result in 'res'. The result's value will be allocated dynamically if
- * necessary and, thus, should be free'd by the caller (e.g. using
- * sdb_data_free_datum). The object may be NULL, in which case the expression
- * needs to evaluate to a constant value. If specified, only objects matching
- * the filter will be used during the evaluation.
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
- sdb_data_t *res, sdb_store_matcher_t *filter);
-
-/*
- * sdb_store_expr_iter:
- * Iterate over the elements of an iterable expression. sdb_store_expr_iter
- * returns NULL if the expression is not iterable (for the specified object).
- *
- * sdb_store_expr_iter_get_next returns NULL if there is no next element.
- */
-sdb_store_expr_iter_t *
-sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
- sdb_store_matcher_t *filter);
-void
-sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter);
-
-bool
-sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter);
-sdb_data_t
-sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter);
-
-/*
- * sdb_store_dis_matcher:
- * Creates a matcher matching the disjunction (logical OR) of two matchers.
- */
-sdb_store_matcher_t *
-sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
-
-/*
- * sdb_store_con_matcher:
- * Creates a matcher matching the conjunction (logical AND) of two matchers.
- */
-sdb_store_matcher_t *
-sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
-
-/*
- * sdb_store_inv_matcher::
- * Creates a matcher matching the inverse (logical NOT) of a matcher.
- */
-sdb_store_matcher_t *
-sdb_store_inv_matcher(sdb_store_matcher_t *m);
-
-/*
- * sdb_store_any_matcher:
- * Creates a matcher iterating over values of the first expression (which has
- * to be iterable). It matches if *any* of those elements match 'm'. 'm' has
- * to be an ary operation with the left operand unset.
- */
-sdb_store_matcher_t *
-sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
-
-/*
- * sdb_store_all_matcher:
- * Creates a matcher iterating over values of the first expression (which has
- * to be iterable). It matches if *all* of those elements match 'm'. 'm' has
- * to be an ary operation with the left operand unset.
- */
-sdb_store_matcher_t *
-sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
-
-/*
- * sdb_store_in_matcher:
- * Creates a matcher which matches if the right value evaluates to an array
- * value and the left value is included in that array. See sdb_data_inarray
- * for more details.
- */
-sdb_store_matcher_t *
-sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-
-/*
- * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
- * sdb_store_ge_matcher, sdb_store_gt_matcher:
- * Create conditional matchers comparing the values of two expressions. The
- * matcher matches if the left expression compres less than, less or equal
- * than, equal to, not equal to, greater or equal than, or greater than the
- * right expression.
- */
-sdb_store_matcher_t *
-sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-sdb_store_matcher_t *
-sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-sdb_store_matcher_t *
-sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-sdb_store_matcher_t *
-sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-sdb_store_matcher_t *
-sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-sdb_store_matcher_t *
-sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-
-/*
- * sdb_store_regex_matcher:
- * Creates a matcher which matches the string value the left expression
- * evaluates to against the regular expression the right expression evaluates
- * to. The right expression may either be a constant value regular expression
- * or string or a dynamic value evaluating to a string. In the latter case,
- * the string is compiled to a regex every time the matcher is executed.
- */
-sdb_store_matcher_t *
-sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-
-/*
- * sdb_store_nregex_matcher:
- * Creates a regex matcher just like sdb_store_regex_matcher except that it
- * matches in case the regular expression does not match.
- */
-sdb_store_matcher_t *
-sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-
-/*
- * sdb_store_isnull_matcher:
- * Creates a matcher matching NULL values.
- */
-sdb_store_matcher_t *
-sdb_store_isnull_matcher(sdb_store_expr_t *expr);
-
-/*
- * sdb_store_istrue_matcher, sdb_store_isfalse_matcher:
- * Creates a matcher matching boolean values.
- */
-sdb_store_matcher_t *
-sdb_store_istrue_matcher(sdb_store_expr_t *expr);
-sdb_store_matcher_t *
-sdb_store_isfalse_matcher(sdb_store_expr_t *expr);
-
-/*
- * sdb_store_matcher_matches:
- * Check whether the specified matcher matches the specified store object. If
- * specified, the filter will be used to preselect objects for further
- * evaluation. It is applied to any object that's used during the evaluation
- * of the matcher. Only those objects matching the filter will be considered.
- *
- * Note that the filter is applied to all object types (hosts, service,
- * metric, attribute). Thus, any object-specific matchers are mostly unsuited
- * for this purpose and, if used, may result in unexpected behavior.
- *
- * Returns:
- * - 1 if the object matches
- * - 0 else
- */
-int
-sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
- sdb_store_matcher_t *filter);
-
-/*
- * sdb_store_matcher_op_cb:
- * Callback constructing a matcher operator.
- */
-typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
- (sdb_store_expr_t *, sdb_store_expr_t *);
-
-/*
- * sdb_store_lookup_cb:
- * Lookup callback. It is called for each matching object when looking up data
- * in the store passing on the lookup filter and the specified user-data. The
- * lookup aborts early if the callback returns non-zero.
- */
-typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
- sdb_store_matcher_t *filter, void *user_data);
-
-/*
- * sdb_store_scan:
- * Look up objects of the specified type in the specified store. The specified
- * callback function is called for each object in the store matching 'm'. The
- * function performs a full scan of all objects stored in the database. If
- * specified, the filter will be used to preselect objects for further
- * evaluation. See the description of 'sdb_store_matcher_matches' for details.
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_scan(sdb_store_t *store, int type,
- sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
- sdb_store_lookup_cb cb, void *user_data);
-
/*
* Flags for JSON formatting.
*/
sdb_store_json_formatter_t *
sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags);
-/*
- * sdb_store_json_emit:
- * Serialize a single object to JSON adding it to the string buffer associated
- * with the formatter object. The serialized object will not include
- * attributes or any child objects. Instead, call the function again for each
- * of those objects. All attributes have to be emitted before any other
- * children types. Use sdb_store_json_emit_full() to emit a full (filtered)
- * object.
- *
- * Note that the output might not be valid JSON before calling
- * sdb_store_json_finish().
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
-
-/*
- * sdb_store_json_emit_full:
- * Serialize a single object including it's attributes and all children to
- * JSON, adding it to the string buffer associated with the formatter object.
- * The filter, if specified, is applied to each attribute and child object.
- * Only matching objects will be included in the output.
- *
- * Note that the output might not be valid JSON before calling
- * sdb_store_json_finish().
- *
- * Returns:
- * - 0 on success
- * - a negative value else
- */
-int
-sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
- sdb_store_matcher_t *filter);
-
/*
* sdb_store_json_finish:
* Finish the JSON output. This function has to be called once after emiting
int
sdb_store_json_finish(sdb_store_json_formatter_t *f);
+/*
+ * sdb_store_json_writer:
+ * A store writer implementation that generates JSON output. It expects a
+ * store JSON formatter as its user-data argument.
+ */
+extern sdb_store_writer_t sdb_store_json_writer;
+
#ifdef __cplusplus
} /* extern "C" */
#endif