[gnumeric] Solver: adapt to glpk file format changes.

[Morten Welinder <mortenw src gnome org>]

commit 0b423b6138c402b8f098941ff2e7ff0f61ee46f6
Author: Morten Welinder <terra gnome org>
Date:   Sun Jan 22 13:15:30 2017 -0500

    Solver: adapt to glpk file format changes.
    
    Glpk changed file format on or about version 4.58

 NEWS                    |    1 +
 plugins/glpk/ChangeLog  |    8 ++
 plugins/glpk/gnm-glpk.c |  183 +++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 171 insertions(+), 21 deletions(-)
---
diff --git a/NEWS b/NEWS
index 51d5939..1230c63 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@ Morten:
        * Bring documentation build into the 21 century.
        * Non-linear solver improvements.
        * Avoid atomizing style regions with conditional formats.
+       * Adapt to glpk file format changes.
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.32
diff --git a/plugins/glpk/ChangeLog b/plugins/glpk/ChangeLog
index ef2e83e..becb1cb 100644
--- a/plugins/glpk/ChangeLog
+++ b/plugins/glpk/ChangeLog
@@ -1,3 +1,11 @@
+2017-01-22  Morten Welinder  <terra gnome org>
+
+       * gnm-glpk.c (gnm_glpk_detect_version): New function.
+       (gnm_glpk_read_solution_457): Extract from gnm_glpk_read_solution.
+       (gnm_glpk_read_solution_458): New function.
+       (gnm_glpk_read_solution): Detect file format version and call
+       appropriate parser.
+
 2016-08-20  Morten Welinder <terra gnome org>
 
        * Release 1.12.32
diff --git a/plugins/glpk/gnm-glpk.c b/plugins/glpk/gnm-glpk.c
index 1ca7d8d..3f8bce6 100644
--- a/plugins/glpk/gnm-glpk.c
+++ b/plugins/glpk/gnm-glpk.c
@@ -101,22 +101,56 @@ parse_number (const char *s)
        return g_ascii_strtod (s, NULL);
 }
 
-static void
-gnm_glpk_read_solution (GnmGlpk *lp)
+typedef enum { GLPK_457, GLPK_458, GLPK_UNKNOWN } GlpkFileVersion;
+
+static GlpkFileVersion
+gnm_glpk_detect_version (GnmGlpk *lp,
+                        GsfInputTextline *tl)
+{
+       GnmSubSolver *subsol = lp->parent;
+       gsf_off_t cur = gsf_input_tell (GSF_INPUT (tl));
+       GlpkFileVersion ver = GLPK_UNKNOWN;
+       const char *line;
+       unsigned cols, rows;
+
+       if ((line = gsf_input_textline_utf8_gets (tl)) == NULL)
+               goto out;
+       if (sscanf (line, "%u %u", &rows, &cols) == 2 &&
+           cols == g_hash_table_size (subsol->cell_from_name)) {
+               ver = GLPK_457;
+               if (gnm_solver_debug ())
+                       g_printerr ("Detected version 4.57 file format\n");
+               goto out;
+       }
+
+       if ((line[0] == 'c' || line[0] == 's') && line[1] == ' ') {
+               ver = GLPK_458;
+               if (gnm_solver_debug ())
+                       g_printerr ("Detected version 4.58 file format\n");
+               goto out;
+       }       
+
+out:
+       // Extra seek due to gsf bug
+       gsf_input_seek (GSF_INPUT (tl), cur + 1, G_SEEK_SET);
+       gsf_input_seek (GSF_INPUT (tl), cur, G_SEEK_SET);
+       return ver;
+}
+
+static gboolean
+gnm_glpk_read_solution_457 (GnmGlpk *lp,
+                           GsfInputTextline *tl,
+                           GnmSolverResult *result,
+                           GnmSolverSensitivity *sensitivity)
 {
        GnmSubSolver *subsol = lp->parent;
        GnmSolver *sol = GNM_SOLVER (subsol);
-       GsfInput *input;
-       GsfInputTextline *tl = NULL;
        const char *line;
-       unsigned rows, cols, c, r;
-       int pstat, dstat;
-       gnm_float val;
-       GnmSolverResult *result = NULL;
-       GnmSolverSensitivity *sensitivity = NULL;
+       unsigned cols, rows, c, r;
        gboolean has_integer;
        GSList *l;
-       enum { SEC_UNKNOWN, SEC_ROWS, SEC_COLUMNS } state;
+       int pstat, dstat;
+       gnm_float val;
 
        /*
         * glpsol's output format is different if there are any integer
@@ -129,17 +163,6 @@ gnm_glpk_read_solution (GnmGlpk *lp)
                               c->type == GNM_SOLVER_BOOLEAN);
        }
 
-       input = gsf_input_stdio_new (lp->result_filename, NULL);
-       if (!input)
-               goto fail;
-       tl = GSF_INPUT_TEXTLINE (gsf_input_textline_new (input));
-       g_object_unref (input);
-
-       result = g_object_new (GNM_SOLVER_RESULT_TYPE, NULL);
-       result->solution = g_new0 (gnm_float, sol->input_cells->len);
-
-       sensitivity = gnm_solver_sensitivity_new (sol);
-
        if ((line = gsf_input_textline_utf8_gets (tl)) == NULL)
                goto fail;
        if (sscanf (line, "%u %u", &rows, &cols) != 2 ||
@@ -209,6 +232,124 @@ gnm_glpk_read_solution (GnmGlpk *lp)
                        sensitivity->vars[idx].reduced_cost = dval;
        }
 
+       // Success
+       return FALSE;
+
+fail:
+       return TRUE;
+}
+
+#define READ_LINE(tl,line) do { line = gsf_input_textline_utf8_gets (tl); if (!line) goto fail; } while 
(line[0] == 'c' && (line[1] == 0 || line[1] == ' '))
+
+static gboolean
+gnm_glpk_read_solution_458 (GnmGlpk *lp,
+                           GsfInputTextline *tl,
+                           GnmSolverResult *result,
+                           GnmSolverSensitivity *sensitivity)
+{
+       GnmSubSolver *subsol = lp->parent;
+       const char *line;
+       unsigned cols, rows, c, r;
+       gnm_float val;
+       char pstat, dstat;
+
+       READ_LINE (tl, line);
+
+       if (sscanf (line, "s %*s %u %u %c %c %" GNM_SCANF_g,
+                   &rows, &cols, &pstat, &dstat, &val) != 5)
+               goto fail;
+       if (cols != g_hash_table_size (subsol->cell_from_name))
+               goto fail;
+
+       result->value = val;
+       switch (pstat) {
+       case 'f':
+               result->quality = GNM_SOLVER_RESULT_OPTIMAL;
+               break;
+       case 'u':
+       case 'i':
+       case 'n':
+               result->quality = GNM_SOLVER_RESULT_INFEASIBLE;
+               break;
+       default:
+               goto fail;
+       }
+
+       for (r = 0; r < rows; r++) {
+               gnm_float pval, dval;
+               char rstat;
+               unsigned r1, cidx = r;
+
+               READ_LINE (tl, line);
+
+               if (sscanf (line, "i %d %c %" GNM_SCANF_g " %" GNM_SCANF_g,
+                           &r1, &rstat, &pval, &dval) != 4 ||
+                   r1 != cidx + 1)
+                       goto fail;
+               // rstat?
+
+               sensitivity->constraints[cidx].shadow_price = dval;
+       }
+
+       for (c = 0; c < cols; c++) {
+               gnm_float pval, dval;
+               char cstat;
+               unsigned c1, cidx = c;
+
+               READ_LINE (tl, line);
+
+               if (sscanf (line, "j %d %c %" GNM_SCANF_g " %" GNM_SCANF_g,
+                           &c1, &cstat, &pval, &dval) != 4 ||
+                   c1 != cidx + 1)
+                       goto fail;
+               // cstat?
+
+               result->solution[cidx] = pval;
+       }
+
+       // Success
+       return FALSE;
+
+fail:
+       return TRUE;
+}
+
+static void
+gnm_glpk_read_solution (GnmGlpk *lp)
+{
+       GnmSubSolver *subsol = lp->parent;
+       GnmSolver *sol = GNM_SOLVER (subsol);
+       GsfInput *input;
+       GsfInputTextline *tl = NULL;
+       const char *line;
+       GnmSolverResult *result = NULL;
+       GnmSolverSensitivity *sensitivity = NULL;
+       enum { SEC_UNKNOWN, SEC_ROWS, SEC_COLUMNS } state;
+
+       input = gsf_input_stdio_new (lp->result_filename, NULL);
+       if (!input)
+               goto fail;
+       tl = GSF_INPUT_TEXTLINE (gsf_input_textline_new (input));
+       g_object_unref (input);
+
+       result = g_object_new (GNM_SOLVER_RESULT_TYPE, NULL);
+       result->solution = g_new0 (gnm_float, sol->input_cells->len);
+
+       sensitivity = gnm_solver_sensitivity_new (sol);
+
+       switch (gnm_glpk_detect_version (lp, tl)) {
+       case GLPK_457:
+               if (gnm_glpk_read_solution_457 (lp, tl, result, sensitivity))
+                       goto fail;
+               break;
+       case GLPK_458:
+               if (gnm_glpk_read_solution_458 (lp, tl, result, sensitivity))
+                       goto fail;
+               break;
+       default:
+               goto fail;
+       }
+
        g_object_unref (tl);
        tl = NULL;