Save fst tables to file

2 files changed, 86 insertions, 58 deletions

diff --git a/TODO.md b/TODO.md
index 23cde09..16e547c 100644
--- a/TODO.md
+++ b/TODO.md
@@ -6,7 +6,6 @@ It's more of a personal reminder than anything else.
 ## After symcoord
 ### Fixing stuff + completing new optimal solver
 - clean up fst, check if more can be improved
-- fst inverse tables: save to file
 ### generic:
 * all files should have an init function, calling the ones
   of the files includes + doing more stuff. A static "initiliazed"
diff --git a/src/fst.c b/src/fst.c
index 7fee732..b51e2d4 100644
--- a/src/fst.c
+++ b/src/fst.c
@@ -6,8 +6,9 @@ static FstCube          ep_to_fst_epos(int *ep);
 static void             init_fst_corner_invtables();
 static void             init_fst_eo_invtables();
 static void             init_fst_eo_update(uint64_t, uint64_t, int, Cube *);
-static void             init_fst_transalg();
 static void             init_fst_where_is_edge();
+static bool             read_fst_tables_file();
+static bool             write_fst_tables_file();
 
 static int edge_slice[12] = {[FR] = 0, [FL] = 0, [BL] = 0, [BR] = 0,
                              [UL] = 1, [UR] = 1, [DR] = 1, [DL] = 1,
@@ -17,12 +18,7 @@ static uint16_t         inv_coud[FACTORIAL8][POW3TO7];
 static uint16_t         inv_cp[FACTORIAL8];
 static uint16_t         uf_cp_to_fr_cp[FACTORIAL8];
 static uint16_t         uf_cp_to_rd_cp[FACTORIAL8];
-
-static int16_t          eo_invtable[3][POW2TO11][BINOM12ON4*FACTORIAL4];
-
-static int              trans_ep_alg[NROTATIONS][12];
-static int              trans_ep_inv[NROTATIONS][12];
-
+static uint16_t         eo_invtable[3][POW2TO11][BINOM12ON4*FACTORIAL4];
 static uint16_t         fst_where_is_edge_arr[3][12][BINOM12ON4*FACTORIAL4];
 
 FstCube
@@ -53,32 +49,6 @@ cube_to_fst(Cube *cube)
 static FstCube
 ep_to_fst_epos(int *ep)
 {
-
-/* The block of commented code works, but it is slower.
-   The actual code is mysterious, and there is some overlap with coord.c
-   (coord_eposepe.i), and trans.c, butbut it is faster. */
-
-/*
-        FstCube ret;
-        Cube c, d;
-
-        make_solved(&c);
-        memcpy(c.ep, ep, 12 * sizeof(int));
-
-        copy_cube(&c, &d);
-        ret.uf_eposepe = coord_eposepe.i[0]->index(&d);
-
-        copy_cube(&c, &d);
-        apply_trans(fr, &d);
-        ret.fr_eposepe = coord_eposepe.i[0]->index(&d);
-
-        copy_cube(&c, &d);
-        apply_trans(rd, &d);
-        ret.rd_eposepe = coord_eposepe.i[0]->index(&d);
-
-        return ret;
-*/
-
         static int eind[12] = {
                 [FR] = 0, [FL] = 1, [BL] = 2, [BR] = 3,
                 [UR] = 0, [DR] = 1, [DL] = 2, [UL] = 3,
@@ -244,10 +214,15 @@ init_fst()
         gen_coord(&coord_coud);
         gen_coord(&coord_cp);
 
-        init_fst_corner_invtables();
-        init_fst_eo_invtables();
-        init_fst_transalg();
-        init_fst_where_is_edge();
+        if (!read_fst_tables_file()) {
+                fprintf(stderr,
+                    "Could not load fst_tables, generating them\n");
+                init_fst_corner_invtables();
+                init_fst_eo_invtables();
+                init_fst_where_is_edge();
+                if (!write_fst_tables_file())
+                        fprintf(stderr, "fst_tables could not be written\b");
+        }
 }
 
 static void
@@ -320,26 +295,6 @@ init_fst_eo_update(uint64_t eo, uint64_t ep, int s, Cube *d)
 }
 
 static void
-init_fst_transalg()
-{
-        Trans t;
-        Alg *alg;
-        Cube c;
-        int i;
-
-        for (t = uf; t < NROTATIONS; t++) {
-                make_solved(&c);
-                alg = rotation_alg(t);
-                apply_alg(alg, &c);
-                for (i = 0; i < 12; i++)
-                        trans_ep_alg[t][i] = c.ep[i];
-                invert_cube_edges(&c);
-                for (i = 0; i < 12; i++)
-                        trans_ep_inv[t][i] = c.ep[i];
-        }
-}
-
-static void
 init_fst_where_is_edge()
 {
         Cube c, d;
@@ -370,3 +325,77 @@ init_fst_where_is_edge()
                 fst_where_is_edge_arr[2][DB][e] = where_is_edge(DB, &d);
         }
 }
+
+static bool
+read_fst_tables_file()
+{
+        init_env();
+
+        FILE *f;
+        char fname[strlen(tabledir)+256];
+        uint64_t i, j, r, total;
+
+        strcpy(fname, tabledir);
+        strcat(fname, "/fst_tables");
+
+        if ((f = fopen(fname, "rb")) == NULL)
+                return false;
+
+        r = 0;
+        total = FACTORIAL8*(POW3TO7+3) + 3*BINOM12ON4*FACTORIAL4*(12+POW2TO11);
+
+        for (i = 0; i < FACTORIAL8; i++)
+                r += fread(inv_coud[i], sizeof(uint16_t), POW3TO7, f);
+        r += fread(inv_cp, sizeof(uint16_t), FACTORIAL8, f);
+        r += fread(uf_cp_to_fr_cp, sizeof(uint16_t), FACTORIAL8, f);
+        r += fread(uf_cp_to_rd_cp, sizeof(uint16_t), FACTORIAL8, f);
+        for (i = 0; i < 3; i++)
+                for (j = 0; j < POW2TO11; j++)
+                        r += fread(eo_invtable[i][j],
+                            sizeof(uint16_t), BINOM12ON4*FACTORIAL4, f);
+        for (i = 0; i < 3; i++)
+                for (j = 0; j < 12; j++)
+                        r += fread(fst_where_is_edge_arr[i][j],
+                            sizeof(uint16_t), BINOM12ON4*FACTORIAL4, f);
+
+        fclose(f);
+
+        return r == total;
+}
+
+static bool
+write_fst_tables_file()
+{
+        init_env();
+
+        FILE *f;
+        char fname[strlen(tabledir)+256];
+        uint64_t i, j, w, total;
+
+        strcpy(fname, tabledir);
+        strcat(fname, "/fst_tables");
+
+        if ((f = fopen(fname, "wb")) == NULL)
+                return false;
+
+        w = 0;
+        total = FACTORIAL8*(POW3TO7+3) + 3*BINOM12ON4*FACTORIAL4*(12+POW2TO11);
+
+        for (i = 0; i < FACTORIAL8; i++)
+                w += fwrite(inv_coud[i], sizeof(uint16_t), POW3TO7, f);
+        w += fwrite(inv_cp, sizeof(uint16_t), FACTORIAL8, f);
+        w += fwrite(uf_cp_to_fr_cp, sizeof(uint16_t), FACTORIAL8, f);
+        w += fwrite(uf_cp_to_rd_cp, sizeof(uint16_t), FACTORIAL8, f);
+        for (i = 0; i < 3; i++)
+                for (j = 0; j < POW2TO11; j++)
+                        w += fwrite(eo_invtable[i][j],
+                            sizeof(uint16_t), BINOM12ON4*FACTORIAL4, f);
+        for (i = 0; i < 3; i++)
+                for (j = 0; j < 12; j++)
+                        w += fwrite(fst_where_is_edge_arr[i][j],
+                            sizeof(uint16_t), BINOM12ON4*FACTORIAL4, f);
+
+        fclose(f);
+
+        return w == total;
+}