X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Finclude%2Fcore%2Fstore.h;h=678af6ff9e706f85a33080ac5a377142e17b0e23;hp=580dce06b9a184c17e0c25ce7bc25b75b312be75;hb=a248a2d506d3caf06d3cf5284231df6fc583087e;hpb=6f5cac1d2144a78fe0e1451758d9af23e8705ebf diff --git a/src/include/core/store.h b/src/include/core/store.h index 580dce0..678af6f 100644 --- a/src/include/core/store.h +++ b/src/include/core/store.h @@ -33,8 +33,10 @@ #include "core/data.h" #include "core/time.h" #include "core/timeseries.h" +#include "parser/ast.h" #include "utils/strbuf.h" +#include #include #ifdef __cplusplus @@ -48,7 +50,8 @@ enum { SDB_HOST = 1, SDB_SERVICE, SDB_METRIC, - SDB_ATTRIBUTE, + + SDB_ATTRIBUTE = 1 << 4, /* * Queryable fields of a stored object. @@ -58,19 +61,28 @@ enum { SDB_FIELD_AGE, /* type: datetime */ SDB_FIELD_INTERVAL, /* type: datetime */ SDB_FIELD_BACKEND, /* type: array of strings */ + SDB_FIELD_VALUE, /* attributes only; type: type of the value */ + SDB_FIELD_TIMESERIES, /* metrics only; type: boolean */ }; #define SDB_STORE_TYPE_TO_NAME(t) \ (((t) == SDB_HOST) ? "host" \ : ((t) == SDB_SERVICE) ? "service" \ : ((t) == SDB_METRIC) ? "metric" \ - : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown") + : ((t) == SDB_ATTRIBUTE) ? "attribute" \ + : ((t) == (SDB_ATTRIBUTE | SDB_HOST)) ? "host attribute" \ + : ((t) == (SDB_ATTRIBUTE | SDB_SERVICE)) ? "service attribute" \ + : ((t) == (SDB_ATTRIBUTE | SDB_METRIC)) ? "metric attribute" \ + : "unknown") #define SDB_FIELD_TO_NAME(f) \ (((f) == SDB_FIELD_NAME) ? "name" \ : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \ : ((f) == SDB_FIELD_AGE) ? "age" \ : ((f) == SDB_FIELD_INTERVAL) ? "interval" \ - : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown") + : ((f) == SDB_FIELD_BACKEND) ? "backend" \ + : ((f) == SDB_FIELD_VALUE) ? "value" \ + : ((f) == SDB_FIELD_TIMESERIES) ? "timeseries" \ + : "unknown") #define SDB_FIELD_TYPE(f) \ (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \ @@ -78,16 +90,34 @@ enum { : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \ : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \ : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \ + : ((f) == SDB_FIELD_VALUE) ? -1 /* unknown */ \ + : ((f) == SDB_FIELD_TIMESERIES) ? SDB_TYPE_BOOLEAN \ : -1) /* - * 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_t represents an in-memory store. It inherits from sdb_object_t + * and may safely be case to a generic object. + */ +struct sdb_store; +typedef struct sdb_store sdb_store_t; +#define SDB_STORE(obj) ((sdb_store_t *)(obj)) + +/* + * sdb_store_obj_t represents the super-class of any stored object. It + * inherits from sdb_object_t and may safely be cast to a generic object to + * access its name. */ struct sdb_store_obj; typedef struct sdb_store_obj sdb_store_obj_t; +/* + * A metric store describes how to access a metric's data. + */ +typedef struct { + const char *type; + const char *id; +} sdb_metric_store_t; + /* * Expressions represent arithmetic expressions based on stored objects and * their various attributes. @@ -99,6 +129,12 @@ struct sdb_store_expr; typedef struct sdb_store_expr sdb_store_expr_t; #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj)) +/* + * 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; + /* * 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 @@ -115,163 +151,187 @@ typedef struct sdb_store_matcher sdb_store_matcher_t; /* * A JSON formatter converts stored objects into the JSON format. * See http://www.ietf.org/rfc/rfc4627.txt + * + * A JSON formatter object inherits from sdb_object_t and, thus, may safely be + * cast to a generic object. */ struct sdb_store_json_formatter; typedef struct sdb_store_json_formatter sdb_store_json_formatter_t; /* - * sdb_store_clear: - * Clear the entire store and remove all stored objects. - */ -void -sdb_store_clear(void); - -/* - * sdb_store_host: - * Add/update a host in the store. If the host, identified by its - * canonicalized name, already exists, it will be updated according to the - * specified name and timestamp. Else, a new entry will be created in the - * store. Any memory required for storing the entry will be allocated an - * managed by the store itself. + * A store writer describes the interface for plugins implementing a store. * - * Returns: + * Any of the call-back functions shall return: * - 0 on success * - a positive value if the new entry is older than the currently stored * entry (in this case, no update will happen) * - a negative value on error */ -int -sdb_store_host(const char *name, sdb_time_t last_update); +typedef struct { + /* + * store_host: + * Add/update a host in the store. If the host, identified by its + * canonicalized name, already exists, it will be updated according to the + * 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); -/* - * sdb_store_has_host: - * sdb_store_get_host: - * Query the store for a host by its (canonicalized) name. - * - * sdb_store_get_host increments the ref count of the host object. The caller - * needs to deref it when no longer using it. - */ -_Bool -sdb_store_has_host(const char *name); + /* + * store_service: + * Add/update a service in the store. If the service, identified by its + * name, already exists for the specified host, it will be updated + * according to the specified name and timestamp. If the referenced host + * 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); -sdb_store_obj_t * -sdb_store_get_host(const char *name); + /* + * store_metric: + * Add/update a metric in the store. If the metric, identified by its + * name, already exists for the specified host, it will be updated + * according to the specified attributes. If the referenced host does not + * 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); + + /* + * store_attribute: + * Add/update a host's attribute in the store. If the attribute, + * identified by its key, already exists for the specified host, it will + * be updated to the specified values. If the referenced host does not + * 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); +} sdb_store_writer_t; /* - * sdb_store_attribute: - * Add/update a host's attribute in the store. If the attribute, identified by - * its key, already exists for the specified host, it will be updated to the - * specified values. If the referenced host does not exist, an error will be - * reported. Else, a new entry will be created in the store. Any memory - * required for storing the entry will be allocated and managed by the store - * itself. - * - * Returns: - * - 0 on success - * - a positive value if the new entry is older than the currently stored - * entry (in this case, no update will happen) - * - a negative value on error + * sdb_store_writer: + * A store writer implementation that provides an in-memory object store. It + * expects a store object as its user-data argument. */ -int -sdb_store_attribute(const char *hostname, - const char *key, const sdb_data_t *value, - sdb_time_t last_update); +extern sdb_store_writer_t sdb_store_writer; /* - * sdb_store_service: - * Add/update a service in the store. If the service, identified by its name, - * already exists for the specified host, it will be updated according to the - * specified 'service' object. If the referenced host does not exist, an error - * will be reported. Else, a new entry will be created in the store. Any - * memory required for storing the entry will be allocated an managed by the - * store itself. - * - * Returns: - * - 0 on success - * - a positive value if the new entry is older than the currently stored - * entry (in this case, no update will happen) - * - a negative value on error + * A store reader describes the interface to query a store implementation. */ -int -sdb_store_service(const char *hostname, const char *name, - sdb_time_t last_update); +typedef struct { + /* + * prepare_query: + * Prepare the query described by 'ast' for execution. + */ + sdb_object_t *(*prepare_query)(sdb_ast_node_t *ast, + sdb_strbuf_t *errbuf, sdb_object_t *user_data); + + /* + * 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. + */ + int (*execute_query)(sdb_object_t *q, + sdb_strbuf_t *buf, sdb_strbuf_t *errbuf, + sdb_object_t *user_data); +} sdb_store_reader_t; /* - * sdb_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. Any memory required for storing - * the entry will be allocated and managed by the store itself. - * - * Returns: - * - 0 on success - * - a positive value if the new entry is older than the currently stored - * entry (in this case, no update will happen) - * - a negative value on error + * sdb_store_reader: + * A store reader implementation that uses an in-memory object store. It + * expects a store object as its user-data argument. */ -int -sdb_store_service_attr(const char *hostname, const char *service, - const char *key, const sdb_data_t *value, sdb_time_t last_update); +extern sdb_store_reader_t sdb_store_reader; /* - * A metric store describes how to access a metric's data. + * sdb_store_create: + * Allocate a new in-memory store. */ -typedef struct { - const char *type; - const char *id; -} sdb_metric_store_t; +sdb_store_t * +sdb_store_create(void); /* - * sdb_store_metric: - * Add/update a metric in the store. If the metric, identified by its name, - * already exists for the specified host, it will be updated according to the - * specified 'metric' object. If the referenced host does not exist, an error - * will be reported. Else, a new entry will be created in the store. Any - * memory required for storing the entry will be allocated an managed by the - * store itself. - * - * If specified, the metric store describes where to access the metric's data. - * - * Returns: - * - 0 on success - * - a positive value if the new entry is older than the currently stored - * entry (in this case, no update will happen) - * - a negative value on error + * 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_metric(const char *hostname, const char *name, - sdb_metric_store_t *store, sdb_time_t last_update); +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_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. Any memory required for storing - * the entry will be allocated and managed by the store itself. + * sdb_store_get_host: + * Query the specified store for a host by its (canonicalized) name. * - * Returns: - * - 0 on success - * - a positive value if the new entry is older than the currently stored - * entry (in this case, no update will happen) - * - a negative value on error + * The function increments the ref count of the host object. The caller needs + * to deref it when no longer using it. */ -int -sdb_store_metric_attr(const char *hostname, const char *metric, - const char *key, const sdb_data_t *value, sdb_time_t last_update); +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. + * 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(const char *hostname, const char *metric, +sdb_store_fetch_timeseries(sdb_store_t *store, + const char *hostname, const char *metric, sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf); /* @@ -295,8 +355,6 @@ sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name); * the returned value. If 'res' is NULL, the function will return whether the * field exists. * - * Note: Retrieving the backend this way is not currently supported. - * * Returns: * - 0 on success * - a negative value else @@ -320,6 +378,62 @@ 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 @@ -332,6 +446,18 @@ sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res, 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 @@ -385,6 +511,24 @@ 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. @@ -400,7 +544,7 @@ sdb_store_matcher_t * sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right); /* - * sdb_store_con_matcher:: + * sdb_store_inv_matcher:: * Creates a matcher matching the inverse (logical NOT) of a matcher. */ sdb_store_matcher_t * @@ -408,19 +552,21 @@ sdb_store_inv_matcher(sdb_store_matcher_t *m); /* * sdb_store_any_matcher: - * Creates a matcher iterating over objects of the specified type. It matches - * if *any* of those objects match 'm'. + * 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(int type, sdb_store_matcher_t *m); +sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m); /* * sdb_store_all_matcher: - * Creates a matcher iterating over objects of the specified type. It matches - * if *all* of those objects match 'm'. + * 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(int type, sdb_store_matcher_t *m); +sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m); /* * sdb_store_in_matcher: @@ -479,11 +625,13 @@ sdb_store_matcher_t * sdb_store_isnull_matcher(sdb_store_expr_t *expr); /* - * sdb_store_isnnull_matcher: - * Creates a matcher matching non-NULL values. + * sdb_store_istrue_matcher, sdb_store_isfalse_matcher: + * Creates a matcher matching boolean values. */ sdb_store_matcher_t * -sdb_store_isnnull_matcher(sdb_store_expr_t *expr); +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: @@ -511,51 +659,6 @@ sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj, typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb) (sdb_store_expr_t *, sdb_store_expr_t *); -/* - * sdb_store_parse_matcher_op: - * Parse a matcher operator and return a constructor for the respective - * matcher. - * - * Returns: - * - matcher operator constructor on success - * - NULL else - */ -sdb_store_matcher_op_cb -sdb_store_parse_matcher_op(const char *op); - -/* - * sdb_store_parse_object_type: - * Parse the type name of a stored object. - * - * Returns: - * - the object type on success - * - a negative value else - */ -int -sdb_store_parse_object_type(const char *name); - -/* - * sdb_store_parse_object_type_plural: - * Parse the type name (plural) of a stored object. - * - * Returns: - * - the object type on success - * - a negative value else - */ -int -sdb_store_parse_object_type_plural(const char *name); - -/* - * sdb_store_parse_field_name: - * Parse the name of a stored object's queryable field. - * - * Returns: - * - the field id on success - * - a negative value else - */ -int -sdb_store_parse_field_name(const char *name); - /* * sdb_store_lookup_cb: * Lookup callback. It is called for each matching object when looking up data @@ -567,18 +670,19 @@ typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj, /* * sdb_store_scan: - * Look up objects of the specified type in the 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. + * 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 stored objects. 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(int type, sdb_store_matcher_t *m, sdb_store_matcher_t *filter, +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); /*