/* EVMC: Ethereum Client-VM Connector API.
* Copyright 2018-2019 The EVMC Authors.
* Licensed under the Apache License, Version 2.0.
*/
#pragma once
#include <evmc/evmc.h>
#include <evmc/helpers.h>
#include <functional>
#include <initializer_list>
#include <utility>
/// EVMC C++ API - wrappers and bindings for C++
/// @ingroup cpp
namespace evmc
{
/// The big-endian 160-bit hash suitable for keeping an Ethereum address.
///
/// This type wraps C ::evmc_address to make sure objects of this type are always initialized.
struct address : evmc_address
{
/// Default and converting constructor.
///
/// Initializes bytes to zeros if not other @p init value provided.
constexpr address(evmc_address init = {}) noexcept : evmc_address{init} {}
/// Converting constructor from unsigned integer value.
///
/// This constructor assigns the @p v value to the last 8 bytes [12:19]
/// in big-endian order.
constexpr explicit address(uint64_t v) noexcept
: evmc_address{{0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
static_cast<uint8_t>(v >> 56),
static_cast<uint8_t>(v >> 48),
static_cast<uint8_t>(v >> 40),
static_cast<uint8_t>(v >> 32),
static_cast<uint8_t>(v >> 24),
static_cast<uint8_t>(v >> 16),
static_cast<uint8_t>(v >> 8),
static_cast<uint8_t>(v >> 0)}}
{}
/// Explicit operator converting to bool.
constexpr inline explicit operator bool() const noexcept;
};
/// The fixed size array of 32 bytes for storing 256-bit EVM values.
///
/// This type wraps C ::evmc_bytes32 to make sure objects of this type are always initialized.
struct bytes32 : evmc_bytes32
{
/// Default and converting constructor.
///
/// Initializes bytes to zeros if not other @p init value provided.
constexpr bytes32(evmc_bytes32 init = {}) noexcept : evmc_bytes32{init} {}
/// Converting constructor from unsigned integer value.
///
/// This constructor assigns the @p v value to the last 8 bytes [24:31]
/// in big-endian order.
constexpr explicit bytes32(uint64_t v) noexcept
: evmc_bytes32{{0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
static_cast<uint8_t>(v >> 56),
static_cast<uint8_t>(v >> 48),
static_cast<uint8_t>(v >> 40),
static_cast<uint8_t>(v >> 32),
static_cast<uint8_t>(v >> 24),
static_cast<uint8_t>(v >> 16),
static_cast<uint8_t>(v >> 8),
static_cast<uint8_t>(v >> 0)}}
{}
/// Explicit operator converting to bool.
constexpr inline explicit operator bool() const noexcept;
};
/// The alias for evmc::bytes32 to represent a big-endian 256-bit integer.
using uint256be = bytes32;
/// Loads 64 bits / 8 bytes of data from the given @p bytes array in big-endian order.
constexpr inline uint64_t load64be(const uint8_t* bytes) noexcept
{
return (uint64_t{bytes[0]} << 56) | (uint64_t{bytes[1]} << 48) | (uint64_t{bytes[2]} << 40) |
(uint64_t{bytes[3]} << 32) | (uint64_t{bytes[4]} << 24) | (uint64_t{bytes[5]} << 16) |
(uint64_t{bytes[6]} << 8) | uint64_t{bytes[7]};
}
/// Loads 32 bits / 4 bytes of data from the given @p bytes array in big-endian order.
constexpr inline uint32_t load32be(const uint8_t* bytes) noexcept
{
return (uint32_t{bytes[0]} << 24) | (uint32_t{bytes[1]} << 16) | (uint32_t{bytes[2]} << 8) |
uint32_t{bytes[3]};
}
namespace fnv
{
constexpr auto prime = 0x100000001b3; ///< The 64-bit FNV prime number.
constexpr auto offset_basis = 0xcbf29ce484222325; ///< The 64-bit FNV offset basis.
/// The hashing transformation for 64-bit inputs based on the FNV-1a formula.
constexpr inline uint64_t fnv1a_by64(uint64_t h, uint64_t x) noexcept
{
return (h ^ x) * prime;
}
} // namespace fnv
/// The "equal to" comparison operator for the evmc::address type.
constexpr bool operator==(const address& a, const address& b) noexcept
{
// TODO: Report bug in clang keeping unnecessary bswap.
return load64be(&a.bytes[0]) == load64be(&b.bytes[0]) &&
load64be(&a.bytes[8]) == load64be(&b.bytes[8]) &&
load32be(&a.bytes[16]) == load32be(&b.bytes[16]);
}
/// The "not equal to" comparison operator for the evmc::address type.
constexpr bool operator!=(const address& a, const address& b) noexcept
{
return !(a == b);
}
/// The "less than" comparison operator for the evmc::address type.
constexpr bool operator<(const address& a, const address& b) noexcept
{
return load64be(&a.bytes[0]) < load64be(&b.bytes[0]) ||
(load64be(&a.bytes[0]) == load64be(&b.bytes[0]) &&
(load64be(&a.bytes[8]) < load64be(&b.bytes[8]) ||
(load64be(&a.bytes[8]) == load64be(&b.bytes[8]) &&
load32be(&a.bytes[16]) < load32be(&b.bytes[16]))));
}
/// The "greater than" comparison operator for the evmc::address type.
constexpr bool operator>(const address& a, const address& b) noexcept
{
return b < a;
}
/// The "less than or equal to" comparison operator for the evmc::address type.
constexpr bool operator<=(const address& a, const address& b) noexcept
{
return !(b < a);
}
/// The "greater than or equal to" comparison operator for the evmc::address type.
constexpr bool operator>=(const address& a, const address& b) noexcept
{
return !(a < b);
}
/// The "equal to" comparison operator for the evmc::bytes32 type.
constexpr bool operator==(const bytes32& a, const bytes32& b) noexcept
{
return load64be(&a.bytes[0]) == load64be(&b.bytes[0]) &&
load64be(&a.bytes[8]) == load64be(&b.bytes[8]) &&
load64be(&a.bytes[16]) == load64be(&b.bytes[16]) &&
load64be(&a.bytes[24]) == load64be(&b.bytes[24]);
}
/// The "not equal to" comparison operator for the evmc::bytes32 type.
constexpr bool operator!=(const bytes32& a, const bytes32& b) noexcept
{
return !(a == b);
}
/// The "less than" comparison operator for the evmc::bytes32 type.
constexpr bool operator<(const bytes32& a, const bytes32& b) noexcept
{
return load64be(&a.bytes[0]) < load64be(&b.bytes[0]) ||
(load64be(&a.bytes[0]) == load64be(&b.bytes[0]) &&
(load64be(&a.bytes[8]) < load64be(&b.bytes[8]) ||
(load64be(&a.bytes[8]) == load64be(&b.bytes[8]) &&
(load64be(&a.bytes[16]) < load64be(&b.bytes[16]) ||
(load64be(&a.bytes[16]) == load64be(&b.bytes[16]) &&
load64be(&a.bytes[24]) < load64be(&b.bytes[24]))))));
}
/// The "greater than" comparison operator for the evmc::bytes32 type.
constexpr bool operator>(const bytes32& a, const bytes32& b) noexcept
{
return b < a;
}
/// The "less than or equal to" comparison operator for the evmc::bytes32 type.
constexpr bool operator<=(const bytes32& a, const bytes32& b) noexcept
{
return !(b < a);
}
/// The "greater than or equal to" comparison operator for the evmc::bytes32 type.
constexpr bool operator>=(const bytes32& a, const bytes32& b) noexcept
{
return !(a < b);
}
/// Checks if the given address is the zero address.
constexpr inline bool is_zero(const address& a) noexcept
{
return a == address{};
}
constexpr address::operator bool() const noexcept
{
return !is_zero(*this);
}
/// Checks if the given bytes32 object has all zero bytes.
constexpr inline bool is_zero(const bytes32& a) noexcept
{
return a == bytes32{};
}
constexpr bytes32::operator bool() const noexcept
{
return !is_zero(*this);
}
namespace literals
{
namespace internal
{
constexpr size_t length(const char* s) noexcept
{
return (*s != '\0') ? length(s + 1) + 1 : 0;
}
constexpr int from_hex(char c) noexcept
{
return (c >= 'a' && c <= 'f') ? c - ('a' - 10) :
(c >= 'A' && c <= 'F') ? c - ('A' - 10) : c - '0';
}
constexpr uint8_t byte(const char* s, size_t i) noexcept
{
return static_cast<uint8_t>((from_hex(s[2 * i]) << 4) | from_hex(s[2 * i + 1]));
}
template <typename T>
T from_hex(const char*) noexcept;
template <>
constexpr bytes32 from_hex<bytes32>(const char* s) noexcept
{
return {
{{byte(s, 0), byte(s, 1), byte(s, 2), byte(s, 3), byte(s, 4), byte(s, 5), byte(s, 6),
byte(s, 7), byte(s, 8), byte(s, 9), byte(s, 10), byte(s, 11), byte(s, 12), byte(s, 13),
byte(s, 14), byte(s, 15), byte(s, 16), byte(s, 17), byte(s, 18), byte(s, 19), byte(s, 20),
byte(s, 21), byte(s, 22), byte(s, 23), byte(s, 24), byte(s, 25), byte(s, 26), byte(s, 27),
byte(s, 28), byte(s, 29), byte(s, 30), byte(s, 31)}}};
}
template <>
constexpr address from_hex<address>(const char* s) noexcept
{
return {
{{byte(s, 0), byte(s, 1), byte(s, 2), byte(s, 3), byte(s, 4), byte(s, 5), byte(s, 6),
byte(s, 7), byte(s, 8), byte(s, 9), byte(s, 10), byte(s, 11), byte(s, 12), byte(s, 13),
byte(s, 14), byte(s, 15), byte(s, 16), byte(s, 17), byte(s, 18), byte(s, 19)}}};
}
template <typename T>
constexpr T from_literal(const char* s)
{
return (s[0] == '0' && s[1] == '\0') ?
T{} :
!(s[0] == '0' && s[1] == 'x') ?
throw "literal must be in hexadecimal notation" :
(length(s + 2) != sizeof(T) * 2) ? throw "literal must match the result type size" :
from_hex<T>(s + 2);
}
} // namespace internal
/// Literal for evmc::address.
constexpr address operator""_address(const char* s) noexcept
{
return internal::from_literal<address>(s);
}
/// Literal for evmc::bytes32.
constexpr bytes32 operator""_bytes32(const char* s) noexcept
{
return internal::from_literal<bytes32>(s);
}
} // namespace literals
using namespace literals;
/// Alias for evmc_make_result().
constexpr auto make_result = evmc_make_result;
/// @copydoc evmc_result
///
/// This is a RAII wrapper for evmc_result and objects of this type
/// automatically release attached resources.
class result : private evmc_result
{
public:
using evmc_result::create_address;
using evmc_result::gas_left;
using evmc_result::output_data;
using evmc_result::output_size;
using evmc_result::status_code;
/// Creates the result from the provided arguments.
///
/// The provided output is copied to memory allocated with malloc()
/// and the evmc_result::release function is set to one invoking free().
///
/// @param _status_code The status code.
/// @param _gas_left The amount of gas left.
/// @param _output_data The pointer to the output.
/// @param _output_size The output size.
result(evmc_status_code _status_code,
int64_t _gas_left,
const uint8_t* _output_data,
size_t _output_size) noexcept
: evmc_result{make_result(_status_code, _gas_left, _output_data, _output_size)}
{}
/// Converting constructor from raw evmc_result.
explicit result(evmc_result const& res) noexcept : evmc_result{res} {}
/// Destructor responsible for automatically releasing attached resources.
~result() noexcept
{
if (release != nullptr)
release(this);
}
/// Move constructor.
result(result&& other) noexcept : evmc_result{other}
{
other.release = nullptr; // Disable releasing of the rvalue object.
}
/// Move assignment operator.
///
/// The self-assigment MUST never happen.
///
/// @param other The other result object.
/// @return The reference to the left-hand side object.
result& operator=(result&& other) noexcept
{
this->~result(); // Release this object.
static_cast<evmc_result&>(*this) = other; // Copy data.
other.release = nullptr; // Disable releasing of the rvalue object.
return *this;
}
/// Releases the ownership and returns the raw copy of evmc_result.
///
/// This method drops the ownership of the result
/// (result's resources are not going to be released when this object is destructed).
/// It is the caller's responsibility having the returned copy of the result to release it.
/// This object MUST NOT be used after this method is invoked.
///
/// @return The copy of this object converted to raw evmc_result.
evmc_result release_raw() noexcept
{
const auto out = evmc_result{*this}; // Copy data.
this->release = nullptr; // Disable releasing of this object.
return out;
}
};
/// The EVMC Host interface
class HostInterface
{
public:
virtual ~HostInterface() noexcept = default;
/// @copydoc evmc_host_interface::account_exists
virtual bool account_exists(const address& addr) const noexcept = 0;
/// @copydoc evmc_host_interface::get_storage
virtual bytes32 get_storage(const address& addr, const bytes32& key) const noexcept = 0;
/// @copydoc evmc_host_interface::set_storage
virtual evmc_storage_status set_storage(const address& addr,
const bytes32& key,
const bytes32& value) noexcept = 0;
/// @copydoc evmc_host_interface::get_balance
virtual uint256be get_balance(const address& addr) const noexcept = 0;
/// @copydoc evmc_host_interface::get_code_size
virtual size_t get_code_size(const address& addr) const noexcept = 0;
/// @copydoc evmc_host_interface::get_code_hash
virtual bytes32 get_code_hash(const address& addr) const noexcept = 0;
/// @copydoc evmc_host_interface::copy_code
virtual size_t copy_code(const address& addr,
size_t code_offset,
uint8_t* buffer_data,
size_t buffer_size) const noexcept = 0;
/// @copydoc evmc_host_interface::selfdestruct
virtual void selfdestruct(const address& addr, const address& beneficiary) noexcept = 0;
/// @copydoc evmc_host_interface::call
virtual result call(const evmc_message& msg) noexcept = 0;
/// @copydoc evmc_host_interface::get_tx_context
virtual evmc_tx_context get_tx_context() const noexcept = 0;
/// @copydoc evmc_host_interface::get_block_hash
virtual bytes32 get_block_hash(int64_t block_number) const noexcept = 0;
/// @copydoc evmc_host_interface::emit_log
virtual void emit_log(const address& addr,
const uint8_t* data,
size_t data_size,
const bytes32 topics[],
size_t num_topics) noexcept = 0;
};
/// Wrapper around EVMC host context / host interface.
///
/// To be used by VM implementations as better alternative to using ::evmc_host_context directly.
class HostContext : public HostInterface
{
const evmc_host_interface* host = nullptr;
evmc_host_context* context = nullptr;
mutable evmc_tx_context tx_context = {};
public:
/// Default constructor for null Host context.
HostContext() = default;
/// Constructor from the EVMC Host primitives.
/// @param interface The reference to the Host interface.
/// @param ctx The pointer to the Host context object. This parameter MAY be null.
HostContext(const evmc_host_interface& interface, evmc_host_context* ctx) noexcept
: host{&interface}, context{ctx}
{}
bool account_exists(const address& address) const noexcept final
{
return host->account_exists(context, &address);
}
bytes32 get_storage(const address& address, const bytes32& key) const noexcept final
{
return host->get_storage(context, &address, &key);
}
evmc_storage_status set_storage(const address& address,
const bytes32& key,
const bytes32& value) noexcept final
{
return host->set_storage(context, &address, &key, &value);
}
uint256be get_balance(const address& address) const noexcept final
{
return host->get_balance(context, &address);
}
size_t get_code_size(const address& address) const noexcept final
{
return host->get_code_size(context, &address);
}
bytes32 get_code_hash(const address& address) const noexcept final
{
return host->get_code_hash(context, &address);
}
size_t copy_code(const address& address,
size_t code_offset,
uint8_t* buffer_data,
size_t buffer_size) const noexcept final
{
return host->copy_code(context, &address, code_offset, buffer_data, buffer_size);
}
void selfdestruct(const address& addr, const address& beneficiary) noexcept final
{
host->selfdestruct(context, &addr, &beneficiary);
}
result call(const evmc_message& message) noexcept final
{
return result{host->call(context, &message)};
}
/// @copydoc HostInterface::get_tx_context()
///
/// The implementation caches the received transaction context
/// by assuming that the block timestamp should never be zero.
///
/// @return The cached transaction context.
evmc_tx_context get_tx_context() const noexcept final
{
if (tx_context.block_timestamp == 0)
tx_context = host->get_tx_context(context);
return tx_context;
}
bytes32 get_block_hash(int64_t number) const noexcept final
{
return host->get_block_hash(context, number);
}
void emit_log(const address& addr,
const uint8_t* data,
size_t data_size,
const bytes32 topics[],
size_t topics_count) noexcept final
{
host->emit_log(context, &addr, data, data_size, topics, topics_count);
}
};
/// Abstract class to be used by Host implementations.
///
/// When implementing EVMC Host, you can directly inherit from the evmc::Host class.
/// This way your implementation will be simpler by avoiding manual handling
/// of the ::evmc_host_context and the ::evmc_host_interface.
class Host : public HostInterface
{
public:
/// Provides access to the global host interface.
/// @returns Reference to the host interface object.
static const evmc_host_interface& get_interface() noexcept;
/// Converts the Host object to the opaque host context pointer.
/// @returns Pointer to evmc_host_context.
evmc_host_context* to_context() noexcept { return reinterpret_cast<evmc_host_context*>(this); }
/// Converts the opaque host context pointer back to the original Host object.
/// @tparam DerivedClass The class derived from the Host class.
/// @param context The opaque host context pointer.
/// @returns The pointer to DerivedClass.
template <typename DerivedClass = Host>
static DerivedClass* from_context(evmc_host_context* context) noexcept
{
// Get pointer of the Host base class.
auto* h = reinterpret_cast<Host*>(context);
// Additional downcast, only possible if DerivedClass inherits from Host.
return static_cast<DerivedClass*>(h);
}
};
/// @copybrief evmc_vm
///
/// This is a RAII wrapper for evmc_vm, and object of this type
/// automatically destroys the VM instance.
class VM
{
public:
VM() noexcept = default;
/// Converting constructor from evmc_vm.
explicit VM(evmc_vm* vm) noexcept : m_instance{vm} {}
/// Destructor responsible for automatically destroying the VM instance.
~VM() noexcept
{
if (m_instance != nullptr)
m_instance->destroy(m_instance);
}
VM(const VM&) = delete;
VM& operator=(const VM&) = delete;
/// Move constructor.
VM(VM&& other) noexcept : m_instance{other.m_instance} { other.m_instance = nullptr; }
/// Move assignment operator.
VM& operator=(VM&& other) noexcept
{
this->~VM();
m_instance = other.m_instance;
other.m_instance = nullptr;
return *this;
}
/// The constructor that captures a VM instance and configures the instance
/// with the provided list of options.
inline VM(evmc_vm* vm,
std::initializer_list<std::pair<const char*, const char*>> options) noexcept;
/// Checks if contains a valid pointer to the VM instance.
explicit operator bool() const noexcept { return m_instance != nullptr; }
/// Checks whenever the VM instance is ABI compatible with the current EVMC API.
bool is_abi_compatible() const noexcept { return m_instance->abi_version == EVMC_ABI_VERSION; }
/// @copydoc evmc_vm::name
char const* name() const noexcept { return m_instance->name; }
/// @copydoc evmc_vm::version
char const* version() const noexcept { return m_instance->version; }
/// Checks if the VM has the given capability.
bool has_capability(evmc_capabilities capability) const noexcept
{
return (get_capabilities() & static_cast<evmc_capabilities_flagset>(capability)) != 0;
}
/// @copydoc evmc::vm::get_capabilities
evmc_capabilities_flagset get_capabilities() const noexcept
{
return m_instance->get_capabilities(m_instance);
}
/// @copydoc evmc_set_option()
evmc_set_option_result set_option(const char name[], const char value[]) noexcept
{
return evmc_set_option(m_instance, name, value);
}
/// @copydoc evmc_execute()
result execute(const evmc_host_interface& host,
evmc_host_context* ctx,
evmc_revision rev,
const evmc_message& msg,
const uint8_t* code,
size_t code_size) noexcept
{
return result{m_instance->execute(m_instance, &host, ctx, rev, &msg, code, code_size)};
}
/// Convenient variant of the VM::execute() that takes reference to evmc::Host class.
result execute(Host& host,
evmc_revision rev,
const evmc_message& msg,
const uint8_t* code,
size_t code_size) noexcept
{
return execute(Host::get_interface(), host.to_context(), rev, msg, code, code_size);
}
/// Executes code without the Host context.
///
/// The same as
/// execute(const evmc_host_interface&, evmc_host_context*, evmc_revision,
/// const evmc_message&, const uint8_t*, size_t),
/// but without providing the Host context and interface.
/// This method is for experimental precompiles support where execution is
/// guaranteed not to require any Host access.
result execute(evmc_revision rev,
const evmc_message& msg,
const uint8_t* code,
size_t code_size) noexcept
{
return result{
m_instance->execute(m_instance, nullptr, nullptr, rev, &msg, code, code_size)};
}
/// Returns the pointer to C EVMC struct representing the VM.
///
/// Gives access to the C EVMC VM struct to allow advanced interaction with the VM not supported
/// by the C++ interface. Use as the last resort.
/// This object still owns the VM after returning the pointer. The returned pointer MAY be null.
evmc_vm* get_raw_pointer() const noexcept { return m_instance; }
private:
evmc_vm* m_instance = nullptr;
};
inline VM::VM(evmc_vm* vm,
std::initializer_list<std::pair<const char*, const char*>> options) noexcept
: m_instance{vm}
{
// This constructor is implemented outside of the class definition to workaround a doxygen bug.
for (const auto& option : options)
set_option(option.first, option.second);
}
namespace internal
{
inline bool account_exists(evmc_host_context* h, const evmc_address* addr) noexcept
{
return Host::from_context(h)->account_exists(*addr);
}
inline evmc_bytes32 get_storage(evmc_host_context* h,
const evmc_address* addr,
const evmc_bytes32* key) noexcept
{
return Host::from_context(h)->get_storage(*addr, *key);
}
inline evmc_storage_status set_storage(evmc_host_context* h,
const evmc_address* addr,
const evmc_bytes32* key,
const evmc_bytes32* value) noexcept
{
return Host::from_context(h)->set_storage(*addr, *key, *value);
}
inline evmc_uint256be get_balance(evmc_host_context* h, const evmc_address* addr) noexcept
{
return Host::from_context(h)->get_balance(*addr);
}
inline size_t get_code_size(evmc_host_context* h, const evmc_address* addr) noexcept
{
return Host::from_context(h)->get_code_size(*addr);
}
inline evmc_bytes32 get_code_hash(evmc_host_context* h, const evmc_address* addr) noexcept
{
return Host::from_context(h)->get_code_hash(*addr);
}
inline size_t copy_code(evmc_host_context* h,
const evmc_address* addr,
size_t code_offset,
uint8_t* buffer_data,
size_t buffer_size) noexcept
{
return Host::from_context(h)->copy_code(*addr, code_offset, buffer_data, buffer_size);
}
inline void selfdestruct(evmc_host_context* h,
const evmc_address* addr,
const evmc_address* beneficiary) noexcept
{
Host::from_context(h)->selfdestruct(*addr, *beneficiary);
}
inline evmc_result call(evmc_host_context* h, const evmc_message* msg) noexcept
{
return Host::from_context(h)->call(*msg).release_raw();
}
inline evmc_tx_context get_tx_context(evmc_host_context* h) noexcept
{
return Host::from_context(h)->get_tx_context();
}
inline evmc_bytes32 get_block_hash(evmc_host_context* h, int64_t block_number) noexcept
{
return Host::from_context(h)->get_block_hash(block_number);
}
inline void emit_log(evmc_host_context* h,
const evmc_address* addr,
const uint8_t* data,
size_t data_size,
const evmc_bytes32 topics[],
size_t num_topics) noexcept
{
Host::from_context(h)->emit_log(*addr, data, data_size, static_cast<const bytes32*>(topics),
num_topics);
}
} // namespace internal
inline const evmc_host_interface& Host::get_interface() noexcept
{
static constexpr evmc_host_interface interface{
::evmc::internal::account_exists, ::evmc::internal::get_storage,
::evmc::internal::set_storage, ::evmc::internal::get_balance,
::evmc::internal::get_code_size, ::evmc::internal::get_code_hash,
::evmc::internal::copy_code, ::evmc::internal::selfdestruct,
::evmc::internal::call, ::evmc::internal::get_tx_context,
::evmc::internal::get_block_hash, ::evmc::internal::emit_log};
return interface;
}
} // namespace evmc
namespace std
{
/// Hash operator template specialization for evmc::address. Needed for unordered containers.
template <>
struct hash<evmc::address>
{
/// Hash operator using FNV1a-based folding.
constexpr size_t operator()(const evmc::address& s) const noexcept
{
using namespace evmc;
using namespace fnv;
return static_cast<size_t>(fnv1a_by64(
fnv1a_by64(fnv1a_by64(fnv::offset_basis, load64be(&s.bytes[0])), load64be(&s.bytes[8])),
load32be(&s.bytes[16])));
}
};
/// Hash operator template specialization for evmc::bytes32. Needed for unordered containers.
template <>
struct hash<evmc::bytes32>
{
/// Hash operator using FNV1a-based folding.
constexpr size_t operator()(const evmc::bytes32& s) const noexcept
{
using namespace evmc;
using namespace fnv;
return static_cast<size_t>(
fnv1a_by64(fnv1a_by64(fnv1a_by64(fnv1a_by64(fnv::offset_basis, load64be(&s.bytes[0])),
load64be(&s.bytes[8])),
load64be(&s.bytes[16])),
load64be(&s.bytes[24])));
}
};
} // namespace std