#include "gettext.h"
#define _(msgid) gettext (msgid)
+/* A casereader that filters data coming from another
+ casereader. */
struct casereader_filter
{
- struct casereader *subreader;
+ struct casereader *subreader; /* The reader to filter. */
bool (*include) (const struct ccase *, void *aux);
bool (*destroy) (void *aux);
void *aux;
- struct casewriter *exclude;
+ struct casewriter *exclude; /* Writer that gets filtered cases, or NULL. */
};
static struct casereader_class casereader_filter_class;
+/* Creates and returns a casereader whose content is a filtered
+ version of the data in SUBREADER. Only the cases for which
+ INCLUDE returns true will appear in the returned casereader,
+ in the original order.
+
+ If EXCLUDE is non-null, then cases for which INCLUDE returns
+ false are written to EXCLUDE. These cases will not
+ necessarily be fully written to EXCLUDE until the filtering casereader's
+ cases have been fully read or, if that never occurs, until the
+ filtering casereader is destroyed.
+
+ When the filtering casereader is destroyed, DESTROY will be
+ called to allow any state maintained by INCLUDE to be freed.
+
+ After this function is called, SUBREADER must not ever again
+ be referenced directly. It will be destroyed automatically
+ when the filtering casereader is destroyed. */
struct casereader *
casereader_create_filter_func (struct casereader *subreader,
bool (*include) (const struct ccase *,
return reader;
}
+/* Internal read function for filtering casereader. */
static bool
casereader_filter_read (struct casereader *reader UNUSED, void *filter_,
struct ccase *c)
}
}
+/* Internal destruction function for filtering casereader. */
static void
casereader_filter_destroy (struct casereader *reader, void *filter_)
{
struct casereader_filter *filter = filter_;
+
+ /* Make sure we've written everything to the excluded cases
+ casewriter, if there is one. */
+ if (filter->exclude != NULL)
+ {
+ struct ccase c;
+ while (casereader_read (filter->subreader, &c))
+ if (filter->include (&c, filter->aux))
+ case_destroy (&c);
+ else
+ casewriter_write (filter->exclude, &c);
+ }
+
casereader_destroy (filter->subreader);
if (filter->destroy != NULL && !filter->destroy (filter->aux))
casereader_force_error (reader);
free (filter);
}
+/* Filtering casereader class. */
static struct casereader_class casereader_filter_class =
{
casereader_filter_read,
NULL,
};
+\f
+/* Casereader for filtering valid weights. */
+
+/* Weight-filtering data. */
struct casereader_filter_weight
{
- const struct variable *weight_var;
- bool *warn_on_invalid;
- bool local_warn_on_invalid;
+ const struct variable *weight_var; /* Weight variable. */
+ bool *warn_on_invalid; /* Have we already issued an error? */
+ bool local_warn_on_invalid; /* warn_on_invalid might point here. */
};
-static bool
-casereader_filter_weight_include (const struct ccase *c, void *cfw_)
-{
- struct casereader_filter_weight *cfw = cfw_;
- double value = case_num (c, cfw->weight_var);
- if (value >= 0.0 && !var_is_num_missing (cfw->weight_var, value, MV_ANY))
- return true;
- else
- {
- if (*cfw->warn_on_invalid)
- {
- msg (SW, _("At least one case in the data read had a weight value "
- "that was user-missing, system-missing, zero, or "
- "negative. These case(s) were ignored."));
- *cfw->warn_on_invalid = false;
- }
- return false;
- }
-}
+static bool casereader_filter_weight_include (const struct ccase *, void *);
+static bool casereader_filter_weight_destroy (void *);
-static bool
-casereader_filter_weight_destroy (void *cfw_)
-{
- struct casereader_filter_weight *cfw = cfw_;
- free (cfw);
- return true;
-}
+/* Creates and returns a casereader that filters cases from
+ READER by valid weights, that is, any cases with user- or
+ system-missing, zero, or negative weights are dropped. The
+ weight variable's information is taken from DICT. If DICT
+ does not have a weight variable, then no cases are filtered
+ out.
+
+ When a case with an invalid weight is encountered,
+ *WARN_ON_INVALID is checked. If it is true, then an error
+ message is issued and *WARN_ON_INVALID is set false. If
+ WARN_ON_INVALID is a null pointer, then an internal bool that
+ is initially true is used instead of a caller-supplied bool.
+ If EXCLUDE is non-null, then dropped cases are written to
+ EXCLUDE. These cases will not necessarily be fully written to
+ EXCLUDE until the filtering casereader's cases have been fully
+ read or, if that never occurs, until the filtering casereader
+ is destroyed.
+
+ After this function is called, READER must not ever again be
+ referenced directly. It will be destroyed automatically when
+ the filtering casereader is destroyed. */
struct casereader *
casereader_create_filter_weight (struct casereader *reader,
const struct dictionary *dict,
reader = casereader_rename (reader);
return reader;
}
-\f
-struct casereader_filter_missing
- {
- struct variable **vars;
- size_t var_cnt;
- enum mv_class class;
- };
+/* Internal "include" function for weight-filtering
+ casereader. */
static bool
-casereader_filter_missing_include (const struct ccase *c, void *cfm_)
+casereader_filter_weight_include (const struct ccase *c, void *cfw_)
{
- const struct casereader_filter_missing *cfm = cfm_;
- size_t i;
-
- for (i = 0; i < cfm->var_cnt; i++)
+ struct casereader_filter_weight *cfw = cfw_;
+ double value = case_num (c, cfw->weight_var);
+ if (value >= 0.0 && !var_is_num_missing (cfw->weight_var, value, MV_ANY))
+ return true;
+ else
{
- struct variable *var = cfm->vars[i];
- const union value *value = case_data (c, var);
- if (var_is_value_missing (var, value, cfm->class))
- return false;
+ if (*cfw->warn_on_invalid)
+ {
+ msg (SW, _("At least one case in the data read had a weight value "
+ "that was user-missing, system-missing, zero, or "
+ "negative. These case(s) were ignored."));
+ *cfw->warn_on_invalid = false;
+ }
+ return false;
}
- return true;
}
+/* Internal "destroy" function for weight-filtering
+ casereader. */
static bool
-casereader_filter_missing_destroy (void *cfm_)
+casereader_filter_weight_destroy (void *cfw_)
{
- struct casereader_filter_missing *cfm = cfm_;
- free (cfm->vars);
- free (cfm);
+ struct casereader_filter_weight *cfw = cfw_;
+ free (cfw);
return true;
}
+\f
+/* Casereader for filtering missing values. */
+
+/* Missing-value filtering data. */
+struct casereader_filter_missing
+ {
+ struct variable **vars; /* Variables whose values to filter. */
+ size_t var_cnt; /* Number of variables. */
+ enum mv_class class; /* Types of missing values to filter. */
+ };
+
+static bool casereader_filter_missing_include (const struct ccase *, void *);
+static bool casereader_filter_missing_destroy (void *);
+
+/* Creates and returns a casereader that filters out cases from
+ READER that have a missing value in the given CLASS for any of
+ the VAR_CNT variables in VARS. Only cases that have
+ non-missing values for all of these variables are passed
+ through.
+ Ownership of VARS is retained by the caller.
+
+ If EXCLUDE is non-null, then dropped cases are written to
+ EXCLUDE. These cases will not necessarily be fully written to
+ EXCLUDE until the filtering casereader's cases have been fully
+ read or, if that never occurs, until the filtering casereader
+ is destroyed.
+
+ After this function is called, READER must not ever again
+ be referenced directly. It will be destroyed automatically
+ when the filtering casereader is destroyed. */
struct casereader *
casereader_create_filter_missing (struct casereader *reader,
const struct variable **vars, size_t var_cnt,
else
return casereader_rename (reader);
}
-\f
-\f
+
+/* Internal "include" function for missing value-filtering
+ casereader. */
static bool
-casereader_counter_include (const struct ccase *c UNUSED, void *counter_)
+casereader_filter_missing_include (const struct ccase *c, void *cfm_)
{
- casenumber *counter = counter_;
- ++*counter;
+ const struct casereader_filter_missing *cfm = cfm_;
+ size_t i;
+
+ for (i = 0; i < cfm->var_cnt; i++)
+ {
+ struct variable *var = cfm->vars[i];
+ const union value *value = case_data (c, var);
+ if (var_is_value_missing (var, value, cfm->class))
+ return false;
+ }
+ return true;
+}
+
+/* Internal "destroy" function for missing value-filtering
+ casereader. */
+static bool
+casereader_filter_missing_destroy (void *cfm_)
+{
+ struct casereader_filter_missing *cfm = cfm_;
+ free (cfm->vars);
+ free (cfm);
return true;
}
+\f
+/* Case-counting casereader. */
+
+static bool casereader_counter_include (const struct ccase *, void *);
+/* Creates and returns a new casereader that counts the number of
+ cases that have been read from it. *COUNTER is initially set
+ to INITIAL_VALUE, then incremented by 1 each time a case is read.
+
+ Counting casereaders must be used very cautiously: if a
+ counting casereader is cloned or if the casereader_peek
+ function is used on it, then the counter's value can be higher
+ than expected because of the buffering that goes on behind the
+ scenes.
+
+ The counter is only incremented as cases are actually read
+ from the casereader. In particular, if the casereader is
+ destroyed before all cases have been read from the casereader,
+ cases never read will not be included in the count.
+
+ After this function is called, READER must not ever again
+ be referenced directly. It will be destroyed automatically
+ when the filtering casereader is destroyed. */
struct casereader *
casereader_create_counter (struct casereader *reader, casenumber *counter,
casenumber initial_value)
return casereader_create_filter_func (reader, casereader_counter_include,
NULL, counter, NULL);
}
+
+/* Internal "include" function for counting casereader. */
+static bool
+casereader_counter_include (const struct ccase *c UNUSED, void *counter_)
+{
+ casenumber *counter = counter_;
+ ++*counter;
+ return true;
+}
projects / pspp-builds.git / blobdiff