diff options
Diffstat (limited to 'docs/abi-spec.rst')
| -rw-r--r-- | docs/abi-spec.rst | 104 |
1 files changed, 56 insertions, 48 deletions
diff --git a/docs/abi-spec.rst b/docs/abi-spec.rst index bf9b8fb7..92af8f0c 100644 --- a/docs/abi-spec.rst +++ b/docs/abi-spec.rst @@ -151,8 +151,8 @@ on the type of ``X`` being - ``bytes``, of length ``k`` (which is assumed to be of type ``uint256``): ``enc(X) = enc(k) pad_right(X)``, i.e. the number of bytes is encoded as a - ``uint256`` followed by the actual value of ``X`` as a byte sequence, followed by - the minimum number of zero-bytes such that ``len(enc(X))`` is a multiple of 32. + ``uint256`` followed by the actual value of ``X`` as a byte sequence, followed by + the minimum number of zero-bytes such that ``len(enc(X))`` is a multiple of 32. - ``string``: @@ -205,7 +205,9 @@ Thus for our ``Foo`` example if we wanted to call ``baz`` with the parameters `` - ``0x0000000000000000000000000000000000000000000000000000000000000045``: the first parameter, a uint32 value ``69`` padded to 32 bytes - ``0x0000000000000000000000000000000000000000000000000000000000000001``: the second parameter - boolean ``true``, padded to 32 bytes -In total:: +In total: + +.. code-block:: none 0xcdcd77c000000000000000000000000000000000000000000000000000000000000000450000000000000000000000000000000000000000000000000000000000000001 @@ -217,7 +219,9 @@ If we wanted to call ``bar`` with the argument ``["abc", "def"]``, we would pass - ``0x6162630000000000000000000000000000000000000000000000000000000000``: the first part of the first parameter, a ``bytes3`` value ``"abc"`` (left-aligned). - ``0x6465660000000000000000000000000000000000000000000000000000000000``: the second part of the first parameter, a ``bytes3`` value ``"def"`` (left-aligned). -In total:: +In total: + +.. code-block:: none 0xfce353f661626300000000000000000000000000000000000000000000000000000000006465660000000000000000000000000000000000000000000000000000000000 @@ -234,7 +238,9 @@ If we wanted to call ``sam`` with the arguments ``"dave"``, ``true`` and ``[1,2, - ``0x0000000000000000000000000000000000000000000000000000000000000002``: the second entry of the third parameter. - ``0x0000000000000000000000000000000000000000000000000000000000000003``: the third entry of the third parameter. -In total:: +In total: + +.. code-block:: none 0xa5643bf20000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000464617665000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000003 @@ -264,7 +270,7 @@ Finally, we encode the data part of the second dynamic argument, ``"Hello, world All together, the encoding is (newline after function selector and each 32-bytes for clarity): -:: +.. code-block:: none 0x8be65246 0000000000000000000000000000000000000000000000000000000000000123 @@ -292,15 +298,15 @@ Then we encode the length and data of the second embedded dynamic array ``[3]`` Then we need to find the offsets ``a`` and ``b`` for their respective dynamic arrays ``[1, 2]`` and ``[3]``. To calculate the offsets we can take a look at the encoded data of the first root array ``[[1, 2], [3]]`` enumerating each line in the encoding: -:: +.. code-block:: none - 0 - a - offset of [1, 2] - 1 - b - offset of [3] - 2 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [1, 2] - 3 - 0000000000000000000000000000000000000000000000000000000000000001 - encoding of 1 - 4 - 0000000000000000000000000000000000000000000000000000000000000002 - encoding of 2 - 5 - 0000000000000000000000000000000000000000000000000000000000000001 - count for [3] - 6 - 0000000000000000000000000000000000000000000000000000000000000003 - encoding of 3 + 0 - a - offset of [1, 2] + 1 - b - offset of [3] + 2 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [1, 2] + 3 - 0000000000000000000000000000000000000000000000000000000000000001 - encoding of 1 + 4 - 0000000000000000000000000000000000000000000000000000000000000002 - encoding of 2 + 5 - 0000000000000000000000000000000000000000000000000000000000000001 - count for [3] + 6 - 0000000000000000000000000000000000000000000000000000000000000003 - encoding of 3 Offset ``a`` points to the start of the content of the array ``[1, 2]`` which is line 2 (64 bytes); thus ``a = 0x0000000000000000000000000000000000000000000000000000000000000040``. @@ -318,17 +324,17 @@ Then we encode the embedded strings of the second root array: In parallel to the first root array, since strings are dynamic elements we need to find their offsets ``c``, ``d`` and ``e``: -:: +.. code-block:: none - 0 - c - offset for "one" - 1 - d - offset for "two" - 2 - e - offset for "three" - 3 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "one" - 4 - 6f6e650000000000000000000000000000000000000000000000000000000000 - encoding of "one" - 5 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "two" - 6 - 74776f0000000000000000000000000000000000000000000000000000000000 - encoding of "two" - 7 - 0000000000000000000000000000000000000000000000000000000000000005 - count for "three" - 8 - 7468726565000000000000000000000000000000000000000000000000000000 - encoding of "three" + 0 - c - offset for "one" + 1 - d - offset for "two" + 2 - e - offset for "three" + 3 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "one" + 4 - 6f6e650000000000000000000000000000000000000000000000000000000000 - encoding of "one" + 5 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "two" + 6 - 74776f0000000000000000000000000000000000000000000000000000000000 - encoding of "two" + 7 - 0000000000000000000000000000000000000000000000000000000000000005 - count for "three" + 8 - 7468726565000000000000000000000000000000000000000000000000000000 - encoding of "three" Offset ``c`` points to the start of the content of the string ``"one"`` which is line 3 (96 bytes); thus ``c = 0x0000000000000000000000000000000000000000000000000000000000000060``. @@ -349,29 +355,29 @@ Then we encode the length of the second root array: Finally we find the offsets ``f`` and ``g`` for their respective root dynamic arrays ``[[1, 2], [3]]`` and ``["one", "two", "three"]``, and assemble parts in the correct order: -:: - - 0x2289b18c - function signature - 0 - f - offset of [[1, 2], [3]] - 1 - g - offset of ["one", "two", "three"] - 2 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [[1, 2], [3]] - 3 - 0000000000000000000000000000000000000000000000000000000000000040 - offset of [1, 2] - 4 - 00000000000000000000000000000000000000000000000000000000000000a0 - offset of [3] - 5 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [1, 2] - 6 - 0000000000000000000000000000000000000000000000000000000000000001 - encoding of 1 - 7 - 0000000000000000000000000000000000000000000000000000000000000002 - encoding of 2 - 8 - 0000000000000000000000000000000000000000000000000000000000000001 - count for [3] - 9 - 0000000000000000000000000000000000000000000000000000000000000003 - encoding of 3 - 10 - 0000000000000000000000000000000000000000000000000000000000000003 - count for ["one", "two", "three"] - 11 - 0000000000000000000000000000000000000000000000000000000000000060 - offset for "one" - 12 - 00000000000000000000000000000000000000000000000000000000000000a0 - offset for "two" - 13 - 00000000000000000000000000000000000000000000000000000000000000e0 - offset for "three" - 14 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "one" - 15 - 6f6e650000000000000000000000000000000000000000000000000000000000 - encoding of "one" - 16 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "two" - 17 - 74776f0000000000000000000000000000000000000000000000000000000000 - encoding of "two" - 18 - 0000000000000000000000000000000000000000000000000000000000000005 - count for "three" - 19 - 7468726565000000000000000000000000000000000000000000000000000000 - encoding of "three" +.. code-block:: none + + 0x2289b18c - function signature + 0 - f - offset of [[1, 2], [3]] + 1 - g - offset of ["one", "two", "three"] + 2 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [[1, 2], [3]] + 3 - 0000000000000000000000000000000000000000000000000000000000000040 - offset of [1, 2] + 4 - 00000000000000000000000000000000000000000000000000000000000000a0 - offset of [3] + 5 - 0000000000000000000000000000000000000000000000000000000000000002 - count for [1, 2] + 6 - 0000000000000000000000000000000000000000000000000000000000000001 - encoding of 1 + 7 - 0000000000000000000000000000000000000000000000000000000000000002 - encoding of 2 + 8 - 0000000000000000000000000000000000000000000000000000000000000001 - count for [3] + 9 - 0000000000000000000000000000000000000000000000000000000000000003 - encoding of 3 + 10 - 0000000000000000000000000000000000000000000000000000000000000003 - count for ["one", "two", "three"] + 11 - 0000000000000000000000000000000000000000000000000000000000000060 - offset for "one" + 12 - 00000000000000000000000000000000000000000000000000000000000000a0 - offset for "two" + 13 - 00000000000000000000000000000000000000000000000000000000000000e0 - offset for "three" + 14 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "one" + 15 - 6f6e650000000000000000000000000000000000000000000000000000000000 - encoding of "one" + 16 - 0000000000000000000000000000000000000000000000000000000000000003 - count for "two" + 17 - 74776f0000000000000000000000000000000000000000000000000000000000 - encoding of "two" + 18 - 0000000000000000000000000000000000000000000000000000000000000005 - count for "three" + 19 - 7468726565000000000000000000000000000000000000000000000000000000 - encoding of "three" Offset ``f`` points to the start of the content of the array ``[[1, 2], [3]]`` which is line 2 (64 bytes); thus ``f = 0x0000000000000000000000000000000000000000000000000000000000000040``. @@ -568,7 +574,9 @@ Through ``abi.encodePacked()``, Solidity supports a non-standard packed mode whe - types shorter than 32 bytes are neither zero padded nor sign extended and - dynamic types are encoded in-place and without the length. -As an example encoding ``int8, bytes1, uint16, string`` with values ``-1, 0x42, 0x2424, "Hello, world!"`` results in :: +As an example encoding ``int8, bytes1, uint16, string`` with values ``-1, 0x42, 0x2424, "Hello, world!"`` results in: + +.. code-block:: none 0xff42242448656c6c6f2c20776f726c6421 ^^ int8(-1) |