1 files changed, 119 insertions, 0 deletions
diff --git a/c_implementation/include/libakfs.h b/c_implementation/include/libakfs.h
new file mode 100644
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+++ b/c_implementation/include/libakfs.h
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+#ifndef AKFS
+#define AKFS
+
+#include <stdbool.h>
+
+/**
+ * This struct represents a HEX output of the SHA-512 algorithm.
+ *
+ */
+typedef struct {
+    /**
+     * The array below has size of 8, which can store the 128 characters into
+     * 16 digit length variables.
+     *
+     * While 512bits/8bits=64bytes, into converting to characters, we use 2bytes
+     * per one digit, which gives us the 128 characters.
+     *
+     */
+    long unsigned int sum[8];
+} sha512sum;
+
+/**
+ * This struct describes explicitly the structure of a root_hash. It is the root
+ * of a hash merkle tree. Note, that this structure can be used for roots and
+ * branches. Possibly, the name will change to something more generic in the
+ * future.
+ * Another note is that instead of approaching this as left and right, as seen
+ * in other codebases, we do a head-tail naming. That's because of the BASH
+ * implementation that you can find at lib/_ak_fs.
+ *
+ */
+typedef struct {
+    /**
+     * Hash of the thing
+     */
+    sha512sum root;
+    /**
+     * Hash of head
+     */
+    sha512sum head;
+    /**
+     * Hash of tail
+     */
+    sha512sum tail;
+} root_hash;
+
+/**
+ * This is the current structure of an akfs_map. Due to potential short-comings
+ * of it, akfs_map_v4 was introduced. Versions v1 and v2 won't be appearing in
+ * this header file, since they were long abandoned. Version v0, on the other
+ * hand, is what is called now as a root_hash. Refer to it for more.
+ *
+ */
+typedef struct {
+    /**
+     * Original file's hash
+     *
+     */
+    sha512sum oh;
+    /**
+     * Original file's name
+     *
+     */
+    char* filename;
+    /**
+     * Root hash
+     *
+     */
+    sha512sum rh;
+    /**
+     * Should be "level.1.map" at all times
+     *
+     */
+    char* root_name;
+} akfs_map_v3;
+
+/**
+ * This is a proposed structure for akfs_map. It is called after its version.
+ * Previous versions have been mostly abandoned, except v3 which is where v4
+ * was derived from. See akfs_map_v3 for more.
+ *
+ */
+typedef struct {
+    /**
+     * Original file's hash
+     *
+     */
+    sha512sum oh;
+    /**
+     * Original filename's AKFS maphash
+     *
+     */
+    sha512sum fn;
+    /**
+     * Root hash
+     *
+     */
+    sha512sum rh;
+} akfs_map_v4;
+
+//typedef char[64] sha512sum_as_string;
+
+char* ak_fs_return_hash_path(char*);
+
+char* ak_fs_return_hash_dir(char*);
+
+bool ak_fs_verify_input_is_hash(char*);
+
+int ak_fs_create_dir_for_hash(char*);
+
+sha512sum ak_fs_sha512sum_string_to_struct(char*);
+
+void ak_fs_sha512sum_struct_to_string(sha512sum, char*);
+
+int ak_fs_open_map_v3(char*);
+int ak_fs_from_map_v3_to_file(akfs_map_v3);
+
+#endif // AKFS
+