Recovering lost commit after rebase

- adding back the tests for ethash_io
- adding back the travis configuration changes
- minor changes to make everything work

io.c

@@ -53,36 +53,31 @@ free_name:
 }
 
 bool ethash_io_write(char const *dirname,
-                     uint32_t block_number,
+                     ethash_params const* params,
+                     ethash_blockhash_t seedhash,
                      void const* cache,
                      uint8_t **data,
                      size_t *data_size)
 {
-    ethash_params p;
     char info_buffer[DAG_MEMO_BYTESIZE];
-    ethash_blockhash_t seedhash;
-
-    p.cache_size = ethash_get_cachesize(block_number);
-    p.full_size = ethash_get_datasize(block_number);
     // allocate the bytes
-    uint8_t *temp_data_ptr = malloc(p.full_size);
-    if (!*temp_data_ptr) {
+    uint8_t *temp_data_ptr = malloc(params->full_size);
+    if (!temp_data_ptr) {
         goto end;
     }
-    ethash_prep_full(temp_data_ptr, &p, cache);
+    ethash_compute_full_data(temp_data_ptr, params, cache);
 
-    if (!ethash_io_write_file(dirname, PASS_ARR(DAG_FILE_NAME), temp_data_ptr, p.full_size)) {
+    if (!ethash_io_write_file(dirname, PASS_ARR(DAG_FILE_NAME), temp_data_ptr, params->full_size)) {
         goto fail_free;
     }
 
-    ethash_get_seedhash((uint8_t*)&seedhash, block_number);
     ethash_io_serialize_info(REVISION, seedhash, info_buffer);
     if (!ethash_io_write_file(dirname, PASS_ARR(DAG_MEMO_NAME), info_buffer, DAG_MEMO_BYTESIZE)) {
         goto fail_free;
     }
 
     *data = temp_data_ptr;
-    *data_size = p.full_size;
+    *data_size = params->full_size;
     return true;
 
 fail_free:

io.h

@@ -62,7 +62,9 @@ enum ethash_io_rc ethash_io_prepare(char const *dirname, ethash_blockhash_t seed
  *
  * @param[in] dirname        A null terminated c-string of the path of the ethash
  *                           data directory. Has to exist.
- * @param[in] block_number   The current block number.
+ * @param[in] params         An ethash_params object containing the full size
+ *                           and the cache size
+ * @param[in] seedhash       The seedhash of the current block number
  * @param[in] cache          The cache data. Would have usually been calulated by
  *                           @see ethash_prep_light().
  * @param[out] data          Pass a pointer to uint8_t by reference here. If the
@@ -76,7 +78,8 @@ enum ethash_io_rc ethash_io_prepare(char const *dirname, ethash_blockhash_t seed
  * @return                   True for success and false in case of failure.
  */
 bool ethash_io_write(char const *dirname,
-                     uint32_t block_number,
+                     ethash_params const* params,
+                     ethash_blockhash_t seedhash,
                      void const* cache,
                      uint8_t **data,
                      size_t *data_size);
@@ -94,7 +97,8 @@ static inline char *ethash_io_create_filename(char const *dirname,
                                               char const* filename,
                                               size_t filename_length)
 {
-    char *name = malloc(strlen(dirname) + filename_length);
+    // in C the cast is not needed, but a C++ compiler will complain for invalid conversion
+    char *name = (char*)malloc(strlen(dirname) + filename_length);
     if (!name) {
         return NULL;
     }