backends now support verion checks

6 files changed, 138 insertions, 38 deletions

diff --git a/include/erasurecode/erasurecode_backend.h b/include/erasurecode/erasurecode_backend.h
index 956b2f1..66e858b 100644
--- a/include/erasurecode/erasurecode_backend.h
+++ b/include/erasurecode/erasurecode_backend.h
@@ -63,6 +63,7 @@ struct ec_backend_args {
 #define FRAGSNEEDED     fragments_needed
 #define RECONSTRUCT     reconstruct
 #define ELEMENTSIZE     element_size
+#define ISCOMPATIBLEWITH    is_compatible_with
 
 #define FN_NAME(s)      str(s)
 #define str(s)          #s
@@ -88,6 +89,8 @@ struct ec_backend_op_stubs {
             char **data, char **parity, int *missing_idxs, int destination_idx,
             int blocksize);
     int (*ELEMENTSIZE)(void *desc);
+
+    bool (*ISCOMPATIBLEWITH) (uint32_t version);
 };
 
 /* ==~=*=~==~=*=~==~=*=~= backend struct definitions =~=*=~==~=*=~==~=*==~== */
@@ -110,6 +113,11 @@ struct ec_backend_common {
                                                      * metadata_adder bytes are added to
                                                      * the fragment size when allocating
                                                      * data/parity fragment buffers */
+    uint32_t                    ec_backend_version; /* The revision number of this back
+                                                     * end. Is used to determine whether
+                                                     * a specific instance of this backend
+                                                     * accepts fragments generated by
+                                                     * another version */
 };
 
 /* EC backend definition */
diff --git a/src/backends/isa-l/isa_l_vand.c b/src/backends/isa-l/isa_l_vand.c
index e7a575e..27a1a99 100644
--- a/src/backends/isa-l/isa_l_vand.c
+++ b/src/backends/isa-l/isa_l_vand.c
@@ -33,9 +33,21 @@
 #include "erasurecode_backend.h"
 #include "erasurecode_helpers.h"
 
+#define ISA_L_RS_VAND_LIB_MAJOR 2
+#define ISA_L_RS_VAND_LIB_MINOR 0
+#define ISA_L_RS_VAND_LIB_REV   0
+#define ISA_L_RS_VAND_LIB_VER_STR "2.0"
+#define ISA_L_RS_VAND_LIB_NAME "isa_l_rs_vand"
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+#define ISA_L_RS_VAND_SO_NAME "isa-l.dylib"
+#else
+#define ISA_L_RS_VAND_SO_NAME "isa-l.so"
+#endif
+
 /* Forward declarations */
 struct ec_backend_op_stubs isa_l_rs_vand_ops;
 struct ec_backend isa_l_rs_vand;
+struct ec_backend_common backend_isa_l_rs_vand;
 
 typedef void (*ec_encode_data_func)(int, int, int, unsigned char*, unsigned char **, unsigned char **);
 typedef void (*ec_init_tables_func)(int, int, unsigned char*, unsigned char *);
@@ -568,6 +580,14 @@ static int isa_l_rs_vand_exit(void *desc)
     return 0;
 }
 
+/*
+ * For the time being, we only claim compatibility with versions that
+ * match exactly
+ */
+static bool isa_l_rs_vand_is_compatible_with(uint32_t version) {
+    return version == backend_isa_l_rs_vand.ec_backend_version;
+}
+
 struct ec_backend_op_stubs isa_l_rs_vand_op_stubs = {
     .INIT                       = isa_l_rs_vand_init,
     .EXIT                       = isa_l_rs_vand_exit,
@@ -576,17 +596,17 @@ struct ec_backend_op_stubs isa_l_rs_vand_op_stubs = {
     .FRAGSNEEDED                = isa_l_rs_vand_min_fragments,
     .RECONSTRUCT                = isa_l_rs_vand_reconstruct,
     .ELEMENTSIZE                = isa_l_rs_vand_element_size,
+    .ISCOMPATIBLEWITH           = isa_l_rs_vand_is_compatible_with,
 };
 
 struct ec_backend_common backend_isa_l_rs_vand = {
     .id                         = EC_BACKEND_ISA_L_RS_VAND,
-    .name                       = "isa_l_rs_vand",
-#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
-    .soname                     = "isa-l.dylib",
-#else
-    .soname                     = "isa-l.so",
-#endif
-    .soversion                  = "2.0",
+    .name                       = ISA_L_RS_VAND_LIB_NAME,
+    .soname                     = ISA_L_RS_VAND_SO_NAME,
+    .soversion                  = ISA_L_RS_VAND_LIB_VER_STR,
     .ops                        = &isa_l_rs_vand_op_stubs,
     .metadata_adder             = 0,
+    .ec_backend_version         = _VERSION(ISA_L_RS_VAND_LIB_MAJOR,
+                                           ISA_L_RS_VAND_LIB_MINOR,
+                                           ISA_L_RS_VAND_LIB_REV),
 };
diff --git a/src/backends/jerasure/jerasure_rs_cauchy.c b/src/backends/jerasure/jerasure_rs_cauchy.c
index 9d8466a..09e7d5c 100644
--- a/src/backends/jerasure/jerasure_rs_cauchy.c
+++ b/src/backends/jerasure/jerasure_rs_cauchy.c
@@ -33,9 +33,21 @@
 #include "erasurecode_backend.h"
 #include "erasurecode_helpers.h"
 
+#define JERASURE_RS_CAUCHY_LIB_MAJOR 2
+#define JERASURE_RS_CAUCHY_LIB_MINOR 0
+#define JERASURE_RS_CAUCHY_LIB_REV   0
+#define JERASURE_RS_CAUCHY_LIB_VER_STR "2.0"
+#define JERASURE_RS_CAUCHY_LIB_NAME "jerasure_rs_cauchy"
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+#define JERASURE_RS_CAUCHY_SO_NAME "libJerasure.dylib"
+#else
+#define JERASURE_RS_CAUCHY_SO_NAME "libJerasure.so"
+#endif
+
 /* Forward declarations */
 struct ec_backend_op_stubs jerasure_rs_cauchy_ops;
 struct ec_backend jerasure_rs_cauchy;
+struct ec_backend_common backend_jerasure_rs_cauchy;
 
 typedef int* (*cauchy_original_coding_matrix_func)(int, int, int);
 typedef int* (*jerasure_matrix_to_bitmatrix_func)(int, int, int, int *);
@@ -364,6 +376,15 @@ static int jerasure_rs_cauchy_exit(void *desc)
     return 0;
 }
 
+/*
+ * For the time being, we only claim compatibility with versions that
+ * match exactly
+ */
+static bool jerasure_rs_cauchy_is_compatible_with(uint32_t version) {
+    return version == backend_jerasure_rs_cauchy.ec_backend_version;
+}
+
+
 struct ec_backend_op_stubs jerasure_rs_cauchy_op_stubs = {
     .INIT                       = jerasure_rs_cauchy_init,
     .EXIT                       = jerasure_rs_cauchy_exit,
@@ -372,17 +393,18 @@ struct ec_backend_op_stubs jerasure_rs_cauchy_op_stubs = {
     .FRAGSNEEDED                = jerasure_rs_cauchy_min_fragments,
     .RECONSTRUCT                = jerasure_rs_cauchy_reconstruct,
     .ELEMENTSIZE                = jerasure_rs_cauchy_element_size,
+    .ISCOMPATIBLEWITH           = jerasure_rs_cauchy_is_compatible_with,
+
 };
 
 struct ec_backend_common backend_jerasure_rs_cauchy = {
     .id                         = EC_BACKEND_JERASURE_RS_CAUCHY,
-    .name                       = "jerasure_rs_cauchy",
-#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
-    .soname                     = "libJerasure.dylib",
-#else
-    .soname                     = "libJerasure.so",
-#endif
-    .soversion                  = "2.0",
+    .name                       = JERASURE_RS_CAUCHY_LIB_NAME,
+    .soname                     = JERASURE_RS_CAUCHY_SO_NAME,
+    .soversion                  = JERASURE_RS_CAUCHY_LIB_VER_STR,
     .ops                        = &jerasure_rs_cauchy_op_stubs,
     .metadata_adder             = 0,
+    .ec_backend_version         = _VERSION(JERASURE_RS_CAUCHY_LIB_MAJOR,
+                                           JERASURE_RS_CAUCHY_LIB_MINOR,
+                                           JERASURE_RS_CAUCHY_LIB_REV),
 };
diff --git a/src/backends/jerasure/jerasure_rs_vand.c b/src/backends/jerasure/jerasure_rs_vand.c
index a8a8257..ed0956e 100644
--- a/src/backends/jerasure/jerasure_rs_vand.c
+++ b/src/backends/jerasure/jerasure_rs_vand.c
@@ -33,9 +33,21 @@
 #include "erasurecode_backend.h"
 #include "erasurecode_helpers.h"
 
+#define JERASURE_RS_VAND_LIB_MAJOR 2
+#define JERASURE_RS_VAND_LIB_MINOR 0
+#define JERASURE_RS_VAND_LIB_REV   0
+#define JERASURE_RS_VAND_LIB_VER_STR "2.0"
+#define JERASURE_RS_VAND_LIB_NAME "jerasure_rs_vand"
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+#define JERASURE_RS_VAND_SO_NAME "libJerasure.dylib"
+#else
+#define JERASURE_RS_VAND_SO_NAME "libJerasure.so"
+#endif
+
 /* Forward declarations */
 struct ec_backend_op_stubs jerasure_rs_vand_ops;
 struct ec_backend jerasure_rs_vand;
+struct ec_backend_common backend_jerasure_rs_vand;
 
 typedef int* (*reed_sol_vandermonde_coding_matrix_func)(int, int, int);
 typedef void (*jerasure_matrix_encode_func)(int, int, int, int*, char **, char **, int); 
@@ -305,6 +317,14 @@ static int jerasure_rs_vand_exit(void *desc)
     return 0;
 }
 
+/*
+ * For the time being, we only claim compatibility with versions that
+ * match exactly
+ */
+static bool jerasure_rs_vand_is_compatible_with(uint32_t version) {
+    return version == backend_jerasure_rs_vand.ec_backend_version;
+}
+
 struct ec_backend_op_stubs jerasure_rs_vand_op_stubs = {
     .INIT                       = jerasure_rs_vand_init,
     .EXIT                       = jerasure_rs_vand_exit,
@@ -313,17 +333,17 @@ struct ec_backend_op_stubs jerasure_rs_vand_op_stubs = {
     .FRAGSNEEDED                = jerasure_rs_vand_min_fragments,
     .RECONSTRUCT                = jerasure_rs_vand_reconstruct,
     .ELEMENTSIZE                = jerasure_rs_vand_element_size,
+    .ISCOMPATIBLEWITH           = jerasure_rs_vand_is_compatible_with,
 };
 
 struct ec_backend_common backend_jerasure_rs_vand = {
     .id                         = EC_BACKEND_JERASURE_RS_VAND,
-    .name                       = "jerasure_rs_vand",
-#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
-    .soname                     = "libJerasure.dylib",
-#else
-    .soname                     = "libJerasure.so",
-#endif
-    .soversion                  = "2.0",
+    .name                       = JERASURE_RS_VAND_LIB_NAME,
+    .soname                     = JERASURE_RS_VAND_SO_NAME,
+    .soversion                  = JERASURE_RS_VAND_LIB_VER_STR,
     .ops                        = &jerasure_rs_vand_op_stubs,
     .metadata_adder             = 0,
+    .ec_backend_version         = _VERSION(JERASURE_RS_VAND_LIB_MAJOR,
+                                           JERASURE_RS_VAND_LIB_MINOR,
+                                           JERASURE_RS_VAND_LIB_REV),
 };
diff --git a/src/backends/null/null.c b/src/backends/null/null.c
index 6ca5c98..294a990 100644
--- a/src/backends/null/null.c
+++ b/src/backends/null/null.c
@@ -31,7 +31,16 @@
 
 #include "erasurecode.h"
 #include "erasurecode_backend.h"
-
+#define NULL_LIB_MAJOR 1
+#define NULL_LIB_MINOR 0
+#define NULL_LIB_REV   0
+#define NULL_LIB_VER_STR "1.0"
+#define NULL_LIB_NAME "null"
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+#define NULL_SO_NAME "libnullcode.dylib"
+#else
+#define NULL_SO_NAME "libnullcode.so"
+#endif
 /* Forward declarations */
 struct ec_backend null;
 struct ec_backend_op_stubs null_ops;
@@ -203,6 +212,9 @@ static int null_exit(void *desc)
     return 0;
 }
 
+static bool null_is_compatible_with(uint32_t version) {
+    return true;
+}
 struct ec_backend_op_stubs null_op_stubs = {
     .INIT                       = null_init,
     .EXIT                       = null_exit,
@@ -211,18 +223,17 @@ struct ec_backend_op_stubs null_op_stubs = {
     .FRAGSNEEDED                = null_min_fragments,
     .RECONSTRUCT                = null_reconstruct,
     .ELEMENTSIZE                = null_element_size,
+    .ISCOMPATIBLEWITH           = null_is_compatible_with,
 };
 
 struct ec_backend_common backend_null = {
     .id                         = EC_BACKEND_NULL,
-    .name                       = "null",
-#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
-    .soname                     = "libnullcode.dylib",
-#else
-    .soname                     = "libnullcode.so",
-#endif
-    .soversion                  = "1.0",
+    .name                       = NULL_LIB_NAME,
+    .soname                     = NULL_SO_NAME,
+    .soversion                  = NULL_LIB_VER_STR,
     .ops                        = &null_op_stubs,
     .metadata_adder             = 0,
+    .ec_backend_version         = _VERSION(NULL_LIB_MAJOR, NULL_LIB_MINOR,
+                                           NULL_LIB_REV),
 };
 
diff --git a/src/backends/xor/flat_xor_hd.c b/src/backends/xor/flat_xor_hd.c
index 0979b30..67a54ae 100644
--- a/src/backends/xor/flat_xor_hd.c
+++ b/src/backends/xor/flat_xor_hd.c
@@ -33,9 +33,22 @@
 #include "erasurecode.h"
 #include "erasurecode_backend.h"
 
+#define FLAT_XOR_LIB_MAJOR 1
+#define FLAT_XOR_LIB_MINOR 0
+#define FLAT_XOR_LIB_REV   0
+#define FLAT_XOR_LIB_VER_STR "1.0"
+#define FLAT_XOR_LIB_NAME "flat_xor_hd"
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+#define FLAT_XOR_SO_NAME "libXorcode.dylib"
+#else
+#define FLAT_XOR_SO_NAME "libXorcode.so"
+#endif
+#define DEFAULT_W 32
+
 /* Forward declarations */
 struct ec_backend_op_stubs flat_xor_hd_ops;
 struct ec_backend flat_xor_hd;
+struct ec_backend_common backend_flat_xor_hd;
 
 typedef xor_code_t* (*init_xor_hd_code_func)(int, int, int);
 typedef void (*xor_code_encode_func)(xor_code_t *, char **, char **, int);
@@ -50,8 +63,6 @@ struct flat_xor_hd_descriptor {
     xor_hd_fragments_needed_func  xor_hd_fragments_needed;
 };
 
-#define DEFAULT_W 32
-
 static int flat_xor_hd_encode(void *desc,
                               char **data, char **parity, int blocksize)
 {
@@ -150,6 +161,14 @@ static int flat_xor_hd_exit(void *desc)
     return 0;
 }
 
+/*
+ * For the time being, we only claim compatibility with versions that
+ * match exactly
+ */
+static bool flat_xor_is_compatible_with(uint32_t version) {
+    return version == backend_flat_xor_hd.ec_backend_version;
+}
+
 struct ec_backend_op_stubs flat_xor_hd_op_stubs = {
     .INIT                       = flat_xor_hd_init,
     .EXIT                       = flat_xor_hd_exit,
@@ -158,18 +177,18 @@ struct ec_backend_op_stubs flat_xor_hd_op_stubs = {
     .FRAGSNEEDED                = flat_xor_hd_min_fragments,
     .RECONSTRUCT                = flat_xor_hd_reconstruct,
     .ELEMENTSIZE                = flar_xor_hd_element_size,
+    .ISCOMPATIBLEWITH           = flat_xor_is_compatible_with,
 };
 
 struct ec_backend_common backend_flat_xor_hd = {
     .id                         = EC_BACKEND_FLAT_XOR_HD,
-    .name                       = "flat_xor_hd",
-#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
-    .soname                     = "libXorcode.dylib",
-#else
-    .soname                     = "libXorcode.so",
-#endif
-    .soversion                  = "1.0",
+    .name                       = FLAT_XOR_LIB_NAME,
+    .soname                     = FLAT_XOR_SO_NAME,
+    .soversion                  = FLAT_XOR_LIB_VER_STR,
     .ops                        = &flat_xor_hd_op_stubs,
     .metadata_adder             = 0,
+    .ec_backend_version         = _VERSION(FLAT_XOR_LIB_MAJOR,
+                                           FLAT_XOR_LIB_MINOR,
+                                           FLAT_XOR_LIB_REV),
 };