8 files changed, 146 insertions, 11 deletions

diff --git a/src/nissy.c b/src/nissy.c
index 0811861..5423d8d 100644
--- a/src/nissy.c
+++ b/src/nissy.c
@@ -328,10 +328,10 @@ nissy_solve(
                 return NISSY_ERROR_INVALID_CUBE;
         }
 
-        if (maxmoves > 20) {
-                LOG("[solve] 'maxmoves' larger than 20 not supported yet, "
-                    "setting it to 20\n");
-                maxmoves = 20;
+        if (maxmoves > SOLUTION_MAXLEN) {
+                LOG("[solve] 'maxmoves' larger than %d not supported yet, "
+                    "setting it to %d\n", SOLUTION_MAXLEN, SOLUTION_MAXLEN);
+                maxmoves = SOLUTION_MAXLEN;
         }
 
         if (minmoves > maxmoves) {
diff --git a/src/solvers/coord/gendata.h b/src/solvers/coord/gendata.h
index 0acf9c0..a48263c 100644
--- a/src/solvers/coord/gendata.h
+++ b/src/solvers/coord/gendata.h
@@ -27,16 +27,25 @@ gendata_coord_dispatch(
         unsigned char *buf
 )
 {
+        size_t r;
         coord_t *coord;
         multicoord_t *mcoord;
 
         parse_coord_and_trans(coordstr, &coord, &mcoord, NULL);
 
-        if (coord != NULL)
-                return gendata_coord(coord, buf);
+        if (coord != NULL) {
+                if (bufsize < gendata_coord(coord, NULL))
+                        return NISSY_ERROR_BUFFER_SIZE;
+                r = gendata_coord(coord, buf);
+                return r == 0 ? NISSY_ERROR_UNKNOWN : (long long)r;
+        }
 
-        if (mcoord != NULL)
-                return gendata_multicoord(mcoord, buf);
+        if (mcoord != NULL) {
+                if (bufsize < gendata_multicoord(mcoord, NULL))
+                        return NISSY_ERROR_BUFFER_SIZE;
+                r = gendata_multicoord(mcoord, buf);
+                return r == 0 ? NISSY_ERROR_UNKNOWN : (long long)r;
+        }
 
         LOG("Error: could not parse coordinate '%s'\n", coordstr);
         return NISSY_ERROR_INVALID_SOLVER;
diff --git a/src/solvers/dispatch.h b/src/solvers/dispatch.h
index d484736..89a0771 100644
--- a/src/solvers/dispatch.h
+++ b/src/solvers/dispatch.h
@@ -41,6 +41,13 @@ solver_dispatch_t solver_dispatchers[] = {
         .solve = solve_multicoord_dispatch,
 },
 {
+        .prefix = "twostep",
+        .dataid = dataid_twostep,
+        .gendata = gendata_twostep,
+        .checkdata = checkdata_twostep,
+        .solve = solve_twostep,
+},
+{
         .prefix = NULL
 }
 };
@@ -70,6 +77,7 @@ const char *solver_aliases[][2] = {
         { "htr-drfb", "coord_HTR_BU" },
         { "corners", "coord_CORNERS_UF" },
         { "cornersx", "coord_CORNERSX_UF" },
+        { "quick", "twostep" },
         { NULL, NULL }
 };
 
diff --git a/src/solvers/solutions_types_macros.h b/src/solvers/solutions_types_macros.h
index 8454a21..6cde681 100644
--- a/src/solvers/solutions_types_macros.h
+++ b/src/solvers/solutions_types_macros.h
@@ -1,7 +1,7 @@
 #ifndef SOLVERS_SOLUTIONS_TYPES_MACROS_H
 #define SOLVERS_SOLUTIONS_TYPES_MACROS_H
 
-#define SOLUTION_MAXLEN 20
+#define SOLUTION_MAXLEN 25
 
 typedef struct {
         uint8_t nmoves;
diff --git a/src/solvers/solvers.h b/src/solvers/solvers.h
index 78180aa..fab6e27 100644
--- a/src/solvers/solvers.h
+++ b/src/solvers/solvers.h
@@ -7,6 +7,7 @@
 #include "tables.h"
 #include "distribution.h"
 #include "coord/coord.h"
+#include "twostep/twostep.h"
 #include "h48/h48.h"
 #include "dispatch.h"
 
diff --git a/src/solvers/twostep/twostep.h b/src/solvers/twostep/twostep.h
new file mode 100644
index 0000000..e5b00f6
--- /dev/null
+++ b/src/solvers/twostep/twostep.h
@@ -0,0 +1,117 @@
+#ifndef SRC_SOLVERS_TWOSTEP_TWOSTEP_H
+#define SRC_SOLVERS_TWOSTEP_TWOSTEP_H
+
+#include "../coord/coord.h"
+
+STATIC size_t twostep_size_1(void);
+STATIC size_t twostep_size_2(void);
+STATIC long long dataid_twostep(const char *, char [SIZE(NISSY_SIZE_DATAID)]);
+STATIC long long gendata_twostep(
+    const char *, unsigned long long, unsigned char *);
+STATIC long long checkdata_twostep(
+    const char *, unsigned long long, const unsigned char *);
+STATIC long long solve_twostep(oriented_cube_t, const char *, unsigned,
+    unsigned, unsigned, unsigned, unsigned, unsigned, unsigned long long,
+    const unsigned char *, unsigned, char *,
+    long long [SIZE(NISSY_SIZE_SOLVE_STATS)], int (*)(void *), void *);
+
+STATIC size_t
+twostep_size_1(void)
+{
+        size_t s;
+
+        s = gendata_coord(&coordinate_dr, NULL);
+        s = (size_t)8 * DIV_ROUND_UP(s, 8); /* Preserve 8-byte alignment */
+
+        return s;
+}
+
+STATIC size_t
+twostep_size_2(void)
+{
+        return gendata_multicoord(&multicoordinate_drfin, NULL);
+}
+
+STATIC long long
+dataid_twostep(const char *s, char dataid[SIZE(NISSY_SIZE_DATAID)])
+{
+        strcpy(dataid, "DR_DRFIN");
+        return NISSY_OK;
+}
+
+STATIC long long
+gendata_twostep(
+        const char *s,
+        unsigned long long bufsize,
+        unsigned char *buf
+)
+{
+        size_t r, s1, s2;
+
+        s1 = twostep_size_1();
+        s2 = twostep_size_2();
+
+        if (buf == NULL)
+                goto gendata_twostep_return_size;
+
+        if (bufsize < s1 + s2)
+                return NISSY_ERROR_BUFFER_SIZE;
+
+        r = gendata_coord(&coordinate_dr, buf);
+        if (r == 0)
+                return NISSY_ERROR_UNKNOWN;
+
+        r = gendata_multicoord(&multicoordinate_drfin, buf + s1);
+        if (r == 0)
+                return NISSY_ERROR_UNKNOWN;
+
+gendata_twostep_return_size:
+        return s1 + s2;
+}
+
+STATIC long long
+checkdata_twostep(
+        const char *s,
+        unsigned long long bufsize,
+        const unsigned char *buf
+)
+{
+        long long r;
+
+        LOG("[checkdata] Checking double table for two step solver\n");
+
+        r = checkdata_coord(&coordinate_dr, bufsize, buf);
+        if (r != NISSY_OK)
+                return r;
+
+        r = checkdata_multicoord(
+            &multicoordinate_drfin, bufsize, buf + twostep_size_1());
+        if (r != NISSY_OK)
+                return r;
+
+        return NISSY_OK;
+}
+
+STATIC long long
+solve_twostep(
+        oriented_cube_t oc,
+        const char *coord_and_trans,
+        unsigned nissflag,
+        unsigned minmoves,
+        unsigned maxmoves,
+        unsigned maxsolutions,
+        unsigned optimal,
+        unsigned threads,
+        unsigned long long data_size,
+        const unsigned char *data,
+        unsigned solutions_size,
+        char *sols,
+        long long stats[SIZE(NISSY_SIZE_SOLVE_STATS)],
+        int (*poll_status)(void *),
+        void *poll_status_data
+)
+{
+//TODO
+}
+
+#endif /* SRC_SOLVERS_TWOSTEP_TWOSTEP_H */
diff --git a/test/140_appendsolution/07_unniss_cancel_nosol.out b/test/140_appendsolution/07_unniss_cancel_nosol.out
index ed5ea65..cd355c7 100644
--- a/test/140_appendsolution/07_unniss_cancel_nosol.out
+++ b/test/140_appendsolution/07_unniss_cancel_nosol.out
@@ -1,3 +1,3 @@
 Number of solutions: 0
-Shortest solution length: 21
+Shortest solution length: 26
 Used bytes: 0
diff --git a/test/140_appendsolution/08_unniss_cancel_nosol_v2.out b/test/140_appendsolution/08_unniss_cancel_nosol_v2.out
index ed5ea65..cd355c7 100644
--- a/test/140_appendsolution/08_unniss_cancel_nosol_v2.out
+++ b/test/140_appendsolution/08_unniss_cancel_nosol_v2.out
@@ -1,3 +1,3 @@
 Number of solutions: 0
-Shortest solution length: 21
+Shortest solution length: 26
 Used bytes: 0