X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdata%2Fcasereader-translator.c;h=5c8b9f4209929f335c702f47e6f96312d8f1fabe;hb=refs%2Fheads%2Frust;hp=d55e18e50292282a6e7c6d95233802fb42c920ed;hpb=a992bf1121d3e1eef76fd6184b95fe079bb91558;p=pspp

diff --git a/src/data/casereader-translator.c b/src/data/casereader-translator.c
index d55e18e502..5c8b9f4209 100644
--- a/src/data/casereader-translator.c
+++ b/src/data/casereader-translator.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2009, 2011 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -15,14 +15,16 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
 #include <config.h>
-#include <data/val-type.h>
-#include <data/casereader.h>
+
 #include <stdlib.h>
 
-#include <data/casereader-provider.h>
-#include <libpspp/taint.h>
+#include "data/casereader-provider.h"
+#include "data/casereader.h"
+#include "data/val-type.h"
+#include "data/variable.h"
+#include "libpspp/taint.h"
 
-#include "xalloc.h"
+#include "gl/xalloc.h"
 
 /* Casereader that applies a user-supplied function to translate
    each case into another in an arbitrary fashion. */
@@ -31,9 +33,7 @@
 struct casereader_translator
   {
     struct casereader *subreader; /* Source of input cases. */
-
-    struct ccase *(*translate) (struct ccase *input, void *aux);
-    bool (*destroy) (void *aux);
+    const struct casereader_translator_class *class;
     void *aux;
   };
 
@@ -41,9 +41,16 @@ static const struct casereader_class casereader_translator_class;
 
 /* Creates and returns a new casereader whose cases are produced
    by reading from SUBREADER and passing through TRANSLATE, which
-   must return the translated case, with OUTPUT_VALUE_CNT values,
-   and populate it based on INPUT and auxiliary data AUX.
-   TRANSLATE must destroy its input case.
+   must return the translated case, and populate it based on
+   INPUT and auxiliary data AUX.  TRANSLATE must destroy its
+   input case.
+
+   TRANSLATE may be stateful, that is, the output for a given
+   case may depend on previous cases.  If TRANSLATE is stateless,
+   then you may want to use casereader_translate_stateless
+   instead, since it sometimes performs better.
+
+   The cases returned by TRANSLATE must match OUTPUT_PROTO.
 
    When the translating casereader is destroyed, DESTROY will be
    called to allow any state maintained by TRANSLATE to be freed.
@@ -53,20 +60,19 @@ static const struct casereader_class casereader_translator_class;
    when the translating casereader is destroyed. */
 struct casereader *
 casereader_create_translator (struct casereader *subreader,
-                              size_t output_value_cnt,
-                              struct ccase *(*translate) (struct ccase *input,
-                                                          void *aux),
-                              bool (*destroy) (void *aux),
+                              const struct caseproto *output_proto,
+                              const struct casereader_translator_class *class,
                               void *aux)
 {
   struct casereader_translator *ct = xmalloc (sizeof *ct);
-  struct casereader *reader;
-  ct->subreader = casereader_rename (subreader);
-  ct->translate = translate;
-  ct->destroy = destroy;
-  ct->aux = aux;
-  reader = casereader_create_sequential (
-    NULL, output_value_cnt, casereader_get_case_cnt (ct->subreader),
+  *ct = (struct casereader_translator) {
+    .subreader = casereader_rename (subreader),
+    .class = class,
+    .aux = aux,
+  };
+
+  struct casereader *reader = casereader_create_sequential (
+    NULL, output_proto, casereader_get_n_cases (ct->subreader),
     &casereader_translator_class, ct);
   taint_propagate (casereader_get_taint (ct->subreader),
                    casereader_get_taint (reader));
@@ -81,7 +87,7 @@ casereader_translator_read (struct casereader *reader UNUSED,
   struct casereader_translator *ct = ct_;
   struct ccase *tmp = casereader_read (ct->subreader);
   if (tmp)
-    tmp = ct->translate (tmp, ct->aux);
+    tmp = ct->class->translate (tmp, ct->aux);
   return tmp;
 }
 
@@ -91,7 +97,7 @@ casereader_translator_destroy (struct casereader *reader UNUSED, void *ct_)
 {
   struct casereader_translator *ct = ct_;
   casereader_destroy (ct->subreader);
-  ct->destroy (ct->aux);
+  ct->class->destroy (ct->aux);
   free (ct);
 }
 
@@ -103,12 +109,107 @@ static const struct casereader_class casereader_translator_class =
     NULL,
     NULL,
   };
+
+/* Casereader that applies a user-supplied function to translate
+   each case into another in a stateless fashion. */
+
+/* A statelessly translating casereader. */
+struct casereader_stateless_translator
+  {
+    struct casereader *subreader; /* Source of input cases. */
 
+    casenumber case_offset;
+    const struct casereader_translator_class *class;
+    void *aux;
+  };
+
+static const struct casereader_random_class
+casereader_stateless_translator_class;
+
+/* Creates and returns a new casereader whose cases are produced by reading
+   from SUBREADER and passing through the TRANSLATE function.  TRANSLATE must
+   takes ownership of its input case and returns a translated case, populating
+   the translated case based on INPUT and auxiliary data AUX.
+
+   TRANSLATE must be stateless, that is, the output for a given case must not
+   depend on previous cases.  This is because cases may be retrieved in
+   arbitrary order, and some cases may be retrieved multiple times, and some
+   cases may be skipped and never retrieved at all.  If TRANSLATE is stateful,
+   use casereader_create_translator instead.
+
+   The cases returned by TRANSLATE must match OUTPUT_PROTO.
+
+   When the stateless translating casereader is destroyed, DESTROY will be
+   called to allow any auxiliary data maintained by TRANSLATE to be freed.
+
+   After this function is called, SUBREADER must not ever again be referenced
+   directly.  It will be destroyed automatically when the translating
+   casereader is destroyed. */
+struct casereader *
+casereader_translate_stateless (
+  struct casereader *subreader,
+  const struct caseproto *output_proto,
+  const struct casereader_translator_class *class,
+  void *aux)
+{
+  struct casereader_stateless_translator *cst = xmalloc (sizeof *cst);
+  *cst = (struct casereader_stateless_translator) {
+    .subreader = casereader_rename (subreader),
+    .class = class,
+    .aux = aux,
+  };
+  struct casereader *reader = casereader_create_random (
+    output_proto, casereader_get_n_cases (cst->subreader),
+    &casereader_stateless_translator_class, cst);
+  taint_propagate (casereader_get_taint (cst->subreader),
+                   casereader_get_taint (reader));
+  return reader;
+}
+
+/* Internal read function for stateless translating casereader. */
+static struct ccase *
+casereader_stateless_translator_read (struct casereader *reader UNUSED,
+                                      void *cst_, casenumber idx)
+{
+  struct casereader_stateless_translator *cst = cst_;
+  struct ccase *tmp = casereader_peek (cst->subreader, idx);
+  if (tmp != NULL)
+    tmp = cst->class->translate (tmp, cst->aux);
+  return tmp;
+}
+
+/* Internal destroy function for translating casereader. */
+static void
+casereader_stateless_translator_destroy (struct casereader *reader UNUSED,
+                                         void *cst_)
+{
+  struct casereader_stateless_translator *cst = cst_;
+  casereader_destroy (cst->subreader);
+  cst->class->destroy (cst->aux);
+  free (cst);
+}
+
+static void
+casereader_stateless_translator_advance (struct casereader *reader UNUSED,
+                                         void *cst_, casenumber n)
+{
+  struct casereader_stateless_translator *cst = cst_;
+  cst->case_offset += casereader_advance (cst->subreader, n);
+}
+
+/* Casereader class for stateless translating casereader. */
+static const struct casereader_random_class
+casereader_stateless_translator_class =
+  {
+    casereader_stateless_translator_read,
+    casereader_stateless_translator_destroy,
+    casereader_stateless_translator_advance,
+  };
 
 
 struct casereader_append_numeric
 {
-  int value_ofs;
+  struct caseproto *proto;
   casenumber n;
   new_value_func *func;
   void *aux;
@@ -135,13 +236,17 @@ casereader_create_append_numeric (struct casereader *subreader,
 				  void (*destroy) (void *aux))
 {
   struct casereader_append_numeric *can = xmalloc (sizeof *can);
-  can->value_ofs = casereader_get_value_cnt (subreader);
+  can->proto = caseproto_ref (casereader_get_proto (subreader));
+  can->proto = caseproto_add_width (can->proto, 0);
   can->n = 0;
   can->aux = aux;
   can->func = func;
   can->destroy = destroy;
-  return casereader_create_translator (subreader, can->value_ofs + 1,
-                                       can_translate, can_destroy, can);
+
+  static const struct casereader_translator_class class = {
+    can_translate, can_destroy,
+  };
+  return casereader_create_translator (subreader, can->proto, &class, can);
 }
 
 
@@ -150,8 +255,8 @@ can_translate (struct ccase *c, void *can_)
 {
   struct casereader_append_numeric *can = can_;
   double new_value = can->func (c, can->n++, can->aux);
-  c = case_unshare_and_resize (c, can->value_ofs + 1);
-  case_data_rw_idx (c, can->value_ofs)->f = new_value;
+  c = case_unshare_and_resize (c, can->proto);
+  *case_num_rw_idx (c, caseproto_get_n_widths (can->proto) - 1) = new_value;
   return c;
 }
 
@@ -161,6 +266,7 @@ can_destroy (void *can_)
   struct casereader_append_numeric *can = can_;
   if (can->destroy)
     can->destroy (can->aux);
+  caseproto_unref (can->proto);
   free (can);
   return true;
 }
@@ -195,7 +301,7 @@ struct casereader *
 casereader_create_arithmetic_sequence (struct casereader *subreader,
                                        double first, double increment)
 {
-  struct arithmetic_sequence *as = xzalloc (sizeof *as);
+  struct arithmetic_sequence *as = XZALLOC (struct arithmetic_sequence);
   as->first = first;
   as->increment = increment;
   return casereader_create_append_numeric (subreader, next_arithmetic,
@@ -211,7 +317,7 @@ struct casereader_append_rank
   casenumber n;
   const struct variable *var;
   const struct variable *weight;
-  int value_ofs;
+  struct caseproto *proto;
   casenumber n_common;
   double mean_rank;
   double cc;
@@ -243,7 +349,7 @@ static struct ccase *car_translate (struct ccase *input, void *car_);
 
    If DISTINCT_CALLBACK is non-null, then  it will be called exactly
    once for every case containing a distinct value of V.  AUX is
-   an auxilliary pointer passed to DISTINCT_CALLBACK.
+   an auxiliary pointer passed to DISTINCT_CALLBACK.
 
    After this function is called, SUBREADER must not ever again
    be referenced directly.  It will be destroyed automatically
@@ -255,10 +361,11 @@ casereader_create_append_rank (struct casereader *subreader,
 			       enum rank_error *err,
 			       distinct_func *distinct_callback,
 			       void *aux
-			       )
+			)
 {
   struct casereader_append_rank *car = xmalloc (sizeof *car);
-  car->value_ofs = casereader_get_value_cnt (subreader);
+  car->proto = caseproto_ref (casereader_get_proto (subreader));
+  car->proto = caseproto_add_width (car->proto, 0);
   car->weight = w;
   car->var = v;
   car->n = 0;
@@ -270,8 +377,10 @@ casereader_create_append_rank (struct casereader *subreader,
   car->err = err;
   car->prev_value = SYSMIS;
 
-  return casereader_create_translator (subreader, car->value_ofs + 1,
-                                       car_translate, car_destroy, car);
+  static const struct casereader_translator_class class = {
+    car_translate, car_destroy
+  };
+  return casereader_create_translator (subreader, car->proto, &class, car);
 }
 
 
@@ -280,6 +389,7 @@ car_destroy (void *car_)
 {
   struct casereader_append_rank *car = car_;
   casereader_destroy (car->clone);
+  caseproto_unref (car->proto);
   free (car);
   return true;
 }
@@ -289,23 +399,23 @@ car_translate (struct ccase *input, void *car_)
 {
   struct casereader_append_rank *car = car_;
 
-  const double value = case_data (input, car->var)->f;
+  const double value = case_num (input, car->var);
 
-  if ( car->prev_value != SYSMIS)
+  if (car->prev_value != SYSMIS)
     {
       if (car->err && value < car->prev_value)
 	*car->err |= RANK_ERR_UNSORTED;
     }
 
-  if ( car->n_common == 1)
+  if (car->n_common == 1)
     {
       double vxx = SYSMIS;
       casenumber k = 0;
       double weight = 1.0;
       if (car->weight)
 	{
-	  weight = case_data (input, car->weight)->f;
-	  if ( car->err && weight < 0 )
+	  weight = case_num (input, car->weight);
+	  if (car->err && weight < 0)
 	    *car->err |= RANK_ERR_NEGATIVE_WEIGHT;
 	}
 
@@ -314,15 +424,15 @@ car_translate (struct ccase *input, void *car_)
 	  struct ccase *c = casereader_peek (car->clone, car->n + ++k);
 	  if (c == NULL)
 	    break;
-	  vxx = case_data (c, car->var)->f;
+	  vxx = case_num (c, car->var);
 
-	  if ( vxx == value)
+	  if (vxx == value)
 	    {
 	      if (car->weight)
 		{
-		  double w = case_data (c, car->weight)->f;
+		  double w = case_num (c, car->weight);
 
-		  if ( car->err && w < 0 )
+		  if (car->err && w < 0)
 		    *car->err |= RANK_ERR_NEGATIVE_WEIGHT;
 
 		  weight += w;
@@ -345,10 +455,142 @@ car_translate (struct ccase *input, void *car_)
 
   car->n++;
 
-  input = case_unshare_and_resize (input, car->value_ofs + 1);
-  case_data_rw_idx (input, car->value_ofs)->f = car->mean_rank ;
+  input = case_unshare_and_resize (input, car->proto);
+  *case_num_rw_idx (input, caseproto_get_n_widths (car->proto) - 1)
+    = car->mean_rank;
   car->prev_value = value;
   return input;
 }
 
 
+
+
+struct consolidator
+{
+  const struct variable *key;
+  const struct variable *weight;
+  double cc;
+  double prev_cc;
+
+  casenumber n;
+  struct casereader *clone;
+  struct caseproto *proto;
+  int direction;
+};
+
+static bool
+uniquify (const struct ccase *c, void *aux)
+{
+  struct consolidator *cdr = aux;
+  const union value *current_value = case_data (c, cdr->key);
+  const int key_width = var_get_width (cdr->key);
+  const double weight = cdr->weight ? case_num (c, cdr->weight) : 1.0;
+  struct ccase *next_case = casereader_peek (cdr->clone, cdr->n + 1);
+  int dir = 0;
+
+  cdr->n ++;
+  cdr->cc += weight;
+
+  if (NULL == next_case)
+      goto end;
+
+  dir = value_compare_3way (case_data (next_case, cdr->key),
+			    current_value, key_width);
+  if (dir > 0)
+    dir = 1;
+  if (dir < 0)
+    dir = -1;
+      
+  case_unref (next_case);
+  if (dir != 0)
+    {
+      /* Insist that the data are sorted */
+      assert (cdr->direction == 0 || dir == cdr->direction);
+      cdr->direction = dir;
+      goto end;
+    }
+
+  return false;
+
+ end:
+  cdr->prev_cc = cdr->cc;
+  cdr->cc = 0;
+  return true;
+}
+
+
+
+static struct ccase *
+consolodate_weight (struct ccase *input, void *aux)
+{
+  struct consolidator *cdr = aux;
+  struct ccase *c;
+
+  if (cdr->weight)
+    {
+      c = case_unshare (input);
+      *case_num_rw (c, cdr->weight) = cdr->prev_cc;
+    }
+  else
+    {
+      c = case_unshare_and_resize (input, cdr->proto);
+      *case_num_rw_idx (c, caseproto_get_n_widths (cdr->proto) - 1) = cdr->prev_cc;
+    }
+
+  return c;
+}
+
+
+static bool
+uniquify_destroy (void *aux)
+{
+  struct consolidator *cdr = aux;
+
+  casereader_destroy (cdr->clone);
+  caseproto_unref (cdr->proto);
+  free (cdr);
+
+  return true;
+}
+
+
+
+/* Returns a new casereader which is based upon INPUT, but which contains a maximum
+   of one case for each distinct value of KEY.
+   If WEIGHT is non-null, then the new casereader's values for this variable
+   will be the sum of all values matching KEY.
+   IF WEIGHT is null, then the new casereader will have an additional numeric
+   value appended, which will contain the total number of cases containing
+   KEY.
+   INPUT must be sorted on KEY
+*/
+struct casereader *
+casereader_create_distinct (struct casereader *input,
+					       const struct variable *key,
+					       const struct variable *weight)
+{
+  struct casereader *u ;
+  struct caseproto *output_proto = caseproto_ref (casereader_get_proto (input));
+
+  struct consolidator *cdr = xmalloc (sizeof (*cdr));
+  cdr->n = 0;
+  cdr->key = key;
+  cdr->weight = weight;
+  cdr->cc = 0;
+  cdr->clone = casereader_clone (input);
+  cdr->direction = 0;
+
+  if (NULL == cdr->weight)
+    output_proto = caseproto_add_width (output_proto, 0);
+
+  cdr->proto = output_proto;
+
+  u = casereader_create_filter_func (input, uniquify,
+				     NULL, cdr, NULL);
+
+  static const struct casereader_translator_class class = {
+    consolodate_weight, uniquify_destroy,
+  };
+  return casereader_create_translator (u, output_proto, &class, cdr);
+}
+