Partial decoder (WIP)

1 files changed, 179 insertions, 0 deletions

diff --git a/include/ecbor.h b/include/ecbor.h
new file mode 100644
index 0000000..a4aed39
--- /dev/null
+++ b/include/ecbor.h
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2018 Vasile Vilvoiu <vasi.vilvoiu@gmail.com>
+ *
+ * libecbor is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _ECBOR_H_
+#define _ECBOR_H_
+
+#include <stdint.h>
+
+/*
+ * Error codes
+ */
+typedef enum {
+  /* no error */
+  ECBOR_OK                                  = 0,
+  ECBOR_ERR_UNKNOWN                         = 1,    /* shouldn't happen, hopefully */
+  
+  /* internal (i.e. misuse) errors */
+  ECBOR_ERR_NULL_CONTEXT                    = 10,
+  ECBOR_ERR_NULL_INPUT_BUFFER               = 11,
+  ECBOR_ERR_NULL_OUTPUT_BUFFER              = 12,
+  ECBOR_ERR_NULL_ITEM_BUFFER                = 13,
+  
+  ECBOR_ERR_NULL_ITEM                       = 20,
+  
+  ECBOR_ERR_WRONG_MODE                      = 30,
+  
+  /* bounds errors */
+  ECBOR_ERR_INVALID_END_OF_BUFFER           = 50,
+  ECBOR_ERR_END_OF_NODE_BUFFER              = 51,
+  
+  /* syntax errors */
+  ECBOR_ERR_CURRENTLY_NOT_SUPPORTED         = 100,
+  ECBOR_ERR_INVALID_ADDITIONAL              = 101,
+  ECBOR_ERR_INVALID_CHUNK_MAJOR_TYPE        = 102,
+  ECBOR_ERR_NESTET_INDEFINITE_STRING        = 103,
+  ECBOR_ERR_INVALID_KEY_VALUE_PAIR          = 104,
+  ECBOR_ERR_INVALID_STOP_CODE               = 105,
+  
+  /* control codes */
+  ECBOR_END_OF_BUFFER                       = 200,
+  ECBOR_END_OF_INDEFINITE                   = 201,
+} ecbor_error_t;
+
+/*
+ * Implementation limits
+ */
+
+/*
+ * CBOR major types
+ */
+typedef enum {
+  ECBOR_MT_UNDEFINED  = -1,
+  ECBOR_MT_UINT       = 0,
+  ECBOR_MT_NINT       = 1,
+  ECBOR_MT_BSTR       = 2,
+  ECBOR_MT_STR        = 3,
+  ECBOR_MT_ARRAY      = 4,
+  ECBOR_MT_MAP        = 5,
+  ECBOR_MT_TAG        = 6,
+  ECBOR_MT_SPECIAL    = 7,
+} ecbor_major_type_t;
+
+/*
+ * CBOR Item
+ */
+typedef struct {
+  /* major type of item */
+  ecbor_major_type_t major_type;
+  
+  /* value */
+  union {
+    uint64_t uinteger;
+    int64_t integer;
+    const uint8_t *string;
+    const uint8_t *items;
+  } value;
+  
+  /* storage size of value, in bytes */
+  uint64_t size;
+  
+  /* number of chunks in value, in case it is indefinite */
+  uint64_t n_chunks;
+  
+  /* non-zero if size is indefinite (for strings, maps and arrays) */
+  uint8_t is_indefinite;
+} ecbor_item_t;
+
+/*
+ * CBOR tree node
+ */
+typedef struct ecbor_node ecbor_node_t;
+struct ecbor_node {
+  ecbor_item_t item;
+  ecbor_node_t *parent;
+  ecbor_node_t *next; /* next in array or map */
+  uint64_t index; /* index in array or map */
+};
+
+/*
+ * Mode
+ */
+typedef enum {
+  ECBOR_MODE_DECODE           = 0,
+  ECBOR_MODE_DECODE_STREAMED  = 1,
+  ECBOR_MODE_DECODE_TREE      = 2,
+  ECBOR_MODE_ENCODE           = 3
+} ecbor_mode_t;
+
+/*
+ * CBOR parsing context
+ */
+typedef struct {
+  /* mode of operation for this context */
+  ecbor_mode_t mode;
+  
+  /* output buffer position */
+  uint8_t *out_position;
+  
+  /* remaining bytes */
+  unsigned int bytes_left;
+} ecbor_encode_context_t;
+ 
+typedef struct {
+  /* mode of operation for this context */
+  ecbor_mode_t mode;
+  
+  /* input buffer position */
+  const uint8_t *in_position;
+  
+  /* remaining bytes */
+  uint64_t bytes_left;
+
+  /* node buffer */
+  ecbor_node_t *nodes;
+  
+  /* capacity of item buffer (in items) */
+  unsigned int node_capacity;
+  
+  /* number of used items so far */
+  unsigned int n_nodes;
+} ecbor_decode_context_t;
+
+
+/*
+ * Initialization routines
+ */
+extern ecbor_error_t
+ecbor_initialize_decode (ecbor_decode_context_t *context,
+                         const uint8_t *buffer,
+                         uint64_t buffer_size);
+
+extern ecbor_error_t
+ecbor_initialize_decode_streamed (ecbor_decode_context_t *context,
+                                  const uint8_t *buffer,
+                                  uint64_t buffer_size);
+
+extern ecbor_error_t
+ecbor_initialize_decode_tree (ecbor_decode_context_t *context,
+                              const uint8_t *buffer,
+                              uint64_t buffer_size,
+                              ecbor_node_t *node_buffer,
+                              uint64_t node_capacity);
+
+
+/*
+ * Decoding routines
+ */
+extern ecbor_error_t
+ecbor_decode (ecbor_decode_context_t *context, ecbor_item_t *item);
+
+/*
+ * Encoding routines
+ */
+
+#endif
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