Add Phazr.IO libphazr backend to liberasurecode

Currently, there are several implementations of erasure codes that are
available within OpenStack Swift.  Most, if not all, of which are based
on the Reed Solomon coding algorithm.

Phazr.IO’s Erasure Coding technology uses a patented algorithm which are
significantly more efficient and improves the speed of coding, decoding
and reconstruction.  In addition, Phazr.IO Erasure Code use a non-systematic
algorithm which provides data protection at rest and in transport without
the need to use encryption.

Please contact support@phazr.io for more info on our technology.

Change-Id: I4e40d02a8951e38409ad3c604c5dd6f050fa7ea0

2 files changed, 23 insertions, 7 deletions

diff --git a/include/erasurecode/erasurecode.h b/include/erasurecode/erasurecode.h
index f5f0fde..0a5f98e 100644
--- a/include/erasurecode/erasurecode.h
+++ b/include/erasurecode/erasurecode.h
@@ -49,6 +49,7 @@ typedef enum {
     EC_BACKEND_SHSS                   = 5,
     EC_BACKEND_LIBERASURECODE_RS_VAND = 6,
     EC_BACKEND_ISA_L_RS_CAUCHY        = 7,
+    EC_BACKEND_LIBPHAZR               = 8,
     EC_BACKENDS_MAX,
 } ec_backend_id_t;
 
diff --git a/include/erasurecode/erasurecode_backend.h b/include/erasurecode/erasurecode_backend.h
index 4199344..2cf7094 100644
--- a/include/erasurecode/erasurecode_backend.h
+++ b/include/erasurecode/erasurecode_backend.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * <Copyright>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -64,6 +64,8 @@ struct ec_backend_args {
 #define RECONSTRUCT     reconstruct
 #define ELEMENTSIZE     element_size
 #define ISCOMPATIBLEWITH    is_compatible_with
+#define GETMETADATASIZE     get_backend_metadata_size
+#define GETENCODEOFFSET     get_encode_offset
 
 #define FN_NAME(s)      str(s)
 #define str(s)          #s
@@ -90,7 +92,10 @@ struct ec_backend_op_stubs {
             int blocksize);
     int (*ELEMENTSIZE)(void *desc);
 
-    bool (*ISCOMPATIBLEWITH) (uint32_t version);
+    bool (*ISCOMPATIBLEWITH)(uint32_t version);
+
+    size_t (*GETMETADATASIZE)(void *desc, int blocksize);
+    size_t (*GETENCODEOFFSET)(void *desc, int metadata_size);
 };
 
 /* ==~=*=~==~=*=~==~=*=~= backend struct definitions =~=*=~==~=*=~==~=*==~== */
@@ -109,11 +114,6 @@ struct ec_backend_common {
     char                        soversion[MAX_LEN]; /* EC backend shared library version */
 
     struct ec_backend_op_stubs  *ops;               /* EC backend stubs */
-    size_t                      backend_metadata_size;
-                                                    /* EC backend custom metadata size -
-                                                     * backend_metadata_size 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
@@ -162,6 +162,21 @@ ec_backend_t liberasurecode_backend_lookup_by_name(const char *name);
  */
 ec_backend_t liberasurecode_backend_instance_get_by_desc(int desc);
 
+/* Common function for backends */
+/**
+ * A function to return 0 for generic usage on backends for get_encode_offset
+ *
+ * Returns 0 always
+ */
+static inline size_t get_encode_offset_zero(void *desc, int metadata_size){ return 0; }
+
+/**
+ * A function to return 0 for generic usage on backends for get_backend_metadata_size
+ *
+ * Returns 0 always
+ */
+static inline size_t get_backend_metadata_size_zero(void *desc, int blocksize){ return 0; }
+
 /* =~=*=~==~=*=~==~=*=~==~=*=~===~=*=~==~=*=~===~=*=~==~=*=~===~=*=~==~=*=~= */
 
 #ifdef __cplusplus