casper-contract 5.1.1

A library for developing Casper network smart contracts.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
//! Functions for accessing and mutating local and global state.

use alloc::{
    collections::{BTreeMap, BTreeSet},
    format,
    string::String,
    vec,
    vec::Vec,
};
use core::{convert::From, mem::MaybeUninit};

use casper_types::{
    addressable_entity::EntryPoints,
    api_error,
    bytesrepr::{self, FromBytes, ToBytes},
    contract_messages::MessageTopicOperation,
    contracts::{ContractHash, ContractPackageHash, ContractVersion, NamedKeys},
    AccessRights, ApiError, CLTyped, CLValue, EntityVersion, HashAddr, Key, URef,
    DICTIONARY_ITEM_KEY_MAX_LENGTH, UREF_SERIALIZED_LENGTH,
};

use crate::{
    contract_api::{self, runtime, runtime::revert},
    ext_ffi,
    unwrap_or_revert::UnwrapOrRevert,
};

/// Reads value under `uref` in the global state.
pub fn read<T: CLTyped + FromBytes>(uref: URef) -> Result<Option<T>, bytesrepr::Error> {
    let key: Key = uref.into();
    read_from_key(key)
}

/// Reads value under `key` in the global state.
pub fn read_from_key<T: CLTyped + FromBytes>(key: Key) -> Result<Option<T>, bytesrepr::Error> {
    let (key_ptr, key_size, _bytes) = contract_api::to_ptr(key);

    let value_size = {
        let mut value_size = MaybeUninit::uninit();
        let ret = unsafe { ext_ffi::casper_read_value(key_ptr, key_size, value_size.as_mut_ptr()) };
        match api_error::result_from(ret) {
            Ok(_) => unsafe { value_size.assume_init() },
            Err(ApiError::ValueNotFound) => return Ok(None),
            Err(e) => runtime::revert(e),
        }
    };

    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    Ok(Some(bytesrepr::deserialize(value_bytes)?))
}

/// Reads value under `uref` in the global state, reverts if value not found or is not `T`.
pub fn read_or_revert<T: CLTyped + FromBytes>(uref: URef) -> T {
    read(uref)
        .unwrap_or_revert_with(ApiError::Read)
        .unwrap_or_revert_with(ApiError::ValueNotFound)
}

/// Writes `value` under `uref` in the global state.
pub fn write<T: CLTyped + ToBytes>(uref: URef, value: T) {
    let key = Key::from(uref);
    let (key_ptr, key_size, _bytes1) = contract_api::to_ptr(key);

    let cl_value = CLValue::from_t(value).unwrap_or_revert();
    let (cl_value_ptr, cl_value_size, _bytes2) = contract_api::to_ptr(cl_value);

    unsafe {
        ext_ffi::casper_write(key_ptr, key_size, cl_value_ptr, cl_value_size);
    }
}

/// Adds `value` to the one currently under `uref` in the global state.
pub fn add<T: CLTyped + ToBytes>(uref: URef, value: T) {
    let key = Key::from(uref);
    let (key_ptr, key_size, _bytes1) = contract_api::to_ptr(key);

    let cl_value = CLValue::from_t(value).unwrap_or_revert();
    let (cl_value_ptr, cl_value_size, _bytes2) = contract_api::to_ptr(cl_value);

    unsafe {
        // Could panic if `value` cannot be added to the given value in memory.
        ext_ffi::casper_add(key_ptr, key_size, cl_value_ptr, cl_value_size);
    }
}

/// Returns a new unforgeable pointer, where the value is initialized to `init`.
pub fn new_uref<T: CLTyped + ToBytes>(init: T) -> URef {
    let uref_non_null_ptr = contract_api::alloc_bytes(UREF_SERIALIZED_LENGTH);
    let cl_value = CLValue::from_t(init).unwrap_or_revert();
    let (cl_value_ptr, cl_value_size, _cl_value_bytes) = contract_api::to_ptr(cl_value);
    let bytes = unsafe {
        ext_ffi::casper_new_uref(uref_non_null_ptr.as_ptr(), cl_value_ptr, cl_value_size); // URef has `READ_ADD_WRITE`
        Vec::from_raw_parts(
            uref_non_null_ptr.as_ptr(),
            UREF_SERIALIZED_LENGTH,
            UREF_SERIALIZED_LENGTH,
        )
    };
    bytesrepr::deserialize(bytes).unwrap_or_revert()
}

/// Create a new contract stored under a Key::Hash at version 1. You may upgrade this contract in
/// the future; if you want a contract that is locked (i.e. cannot be upgraded) call
/// `new_locked_contract` instead.
/// if `named_keys` is provided, puts all of the included named keys into the newly created
///     contract version's named keys.
/// if `hash_name` is provided, puts Key::Hash(contract_package_hash) into the
///     installing account's named keys under `hash_name`.
/// if `uref_name` is provided, puts Key::URef(access_uref) into the installing account's named
///     keys under `uref_name`
pub fn new_contract(
    entry_points: EntryPoints,
    named_keys: Option<NamedKeys>,
    hash_name: Option<String>,
    uref_name: Option<String>,
    message_topics: Option<BTreeMap<String, MessageTopicOperation>>,
) -> (ContractHash, EntityVersion) {
    create_contract(
        entry_points,
        named_keys,
        hash_name,
        uref_name,
        message_topics,
        false,
    )
}

/// Create a locked contract stored under a Key::Hash, which can never be upgraded. This is an
/// irreversible decision; for a contract that can be upgraded use `new_contract` instead.
/// if `named_keys` is provided, puts all of the included named keys into the newly created
///     contract version's named keys.
/// if `hash_name` is provided, puts Key::Hash(contract_package_hash) into the
///     installing account's named keys under `hash_name`.
/// if `uref_name` is provided, puts Key::URef(access_uref) into the installing account's named
///     keys under `uref_name`
pub fn new_locked_contract(
    entry_points: EntryPoints,
    named_keys: Option<NamedKeys>,
    hash_name: Option<String>,
    uref_name: Option<String>,
    message_topics: Option<BTreeMap<String, MessageTopicOperation>>,
) -> (ContractHash, EntityVersion) {
    create_contract(
        entry_points,
        named_keys,
        hash_name,
        uref_name,
        message_topics,
        true,
    )
}

fn create_contract(
    entry_points: EntryPoints,
    named_keys: Option<NamedKeys>,
    hash_name: Option<String>,
    uref_name: Option<String>,
    message_topics: Option<BTreeMap<String, MessageTopicOperation>>,
    is_locked: bool,
) -> (ContractHash, EntityVersion) {
    let (contract_package_hash, access_uref) = create_contract_package(is_locked);

    if let Some(hash_name) = hash_name {
        runtime::put_key(&hash_name, Key::Hash(contract_package_hash.value()));
    };

    if let Some(uref_name) = uref_name {
        runtime::put_key(&uref_name, access_uref.into());
    };

    let named_keys = named_keys.unwrap_or_default();

    let message_topics = message_topics.unwrap_or_default();

    add_contract_version(
        contract_package_hash,
        entry_points,
        named_keys,
        message_topics,
    )
}

/// Create a new (versioned) contract stored under a Key::Hash. Initially there
/// are no versions; a version must be added via `add_contract_version` before
/// the contract can be executed.
pub fn create_contract_package_at_hash() -> (ContractPackageHash, URef) {
    create_contract_package(false)
}

fn create_contract_package(is_locked: bool) -> (ContractPackageHash, URef) {
    let mut hash_addr: HashAddr = ContractPackageHash::default().value();
    let mut access_addr = [0u8; 32];
    unsafe {
        ext_ffi::casper_create_contract_package_at_hash(
            hash_addr.as_mut_ptr(),
            access_addr.as_mut_ptr(),
            is_locked,
        );
    }
    let contract_package_hash: ContractPackageHash = hash_addr.into();
    let access_uref = URef::new(access_addr, AccessRights::READ_ADD_WRITE);

    (contract_package_hash, access_uref)
}

/// Create a new "user group" for a (versioned) contract. User groups associate
/// a set of URefs with a label. Entry points on a contract can be given a list of
/// labels they accept and the runtime will check that a URef from at least one
/// of the allowed groups is present in the caller's context before
/// execution. This allows access control for entry_points of a contract. This
/// function returns the list of new URefs created for the group (the list will
/// contain `num_new_urefs` elements).
pub fn create_contract_user_group(
    contract_package_hash: ContractPackageHash,
    group_label: &str,
    num_new_urefs: u8, // number of new urefs to populate the group with
    existing_urefs: BTreeSet<URef>, // also include these existing urefs in the group
) -> Result<Vec<URef>, ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(contract_package_hash);
    let (label_ptr, label_size, _bytes3) = contract_api::to_ptr(group_label);
    let (existing_urefs_ptr, existing_urefs_size, _bytes4) = contract_api::to_ptr(existing_urefs);

    let value_size = {
        let mut output_size = MaybeUninit::uninit();
        let ret = unsafe {
            ext_ffi::casper_create_contract_user_group(
                contract_package_hash_ptr,
                contract_package_hash_size,
                label_ptr,
                label_size,
                num_new_urefs,
                existing_urefs_ptr,
                existing_urefs_size,
                output_size.as_mut_ptr(),
            )
        };
        api_error::result_from(ret).unwrap_or_revert();
        unsafe { output_size.assume_init() }
    };

    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    Ok(bytesrepr::deserialize(value_bytes).unwrap_or_revert())
}

/// Extends specified group with a new `URef`.
pub fn provision_contract_user_group_uref(
    package_hash: ContractPackageHash,
    label: &str,
) -> Result<URef, ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(package_hash);
    let (label_ptr, label_size, _bytes2) = contract_api::to_ptr(label);
    let value_size = {
        let mut value_size = MaybeUninit::uninit();
        let ret = unsafe {
            ext_ffi::casper_provision_contract_user_group_uref(
                contract_package_hash_ptr,
                contract_package_hash_size,
                label_ptr,
                label_size,
                value_size.as_mut_ptr(),
            )
        };
        api_error::result_from(ret)?;
        unsafe { value_size.assume_init() }
    };
    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    Ok(bytesrepr::deserialize(value_bytes).unwrap_or_revert())
}

/// Removes specified urefs from a named group.
pub fn remove_contract_user_group_urefs(
    package_hash: ContractPackageHash,
    label: &str,
    urefs: BTreeSet<URef>,
) -> Result<(), ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(package_hash);
    let (label_ptr, label_size, _bytes3) = contract_api::to_ptr(label);
    let (urefs_ptr, urefs_size, _bytes4) = contract_api::to_ptr(urefs);
    let ret = unsafe {
        ext_ffi::casper_remove_contract_user_group_urefs(
            contract_package_hash_ptr,
            contract_package_hash_size,
            label_ptr,
            label_size,
            urefs_ptr,
            urefs_size,
        )
    };
    api_error::result_from(ret)
}

/// Remove a named group from given contract.
pub fn remove_contract_user_group(
    package_hash: ContractPackageHash,
    label: &str,
) -> Result<(), ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(package_hash);
    let (label_ptr, label_size, _bytes3) = contract_api::to_ptr(label);
    let ret = unsafe {
        ext_ffi::casper_remove_contract_user_group(
            contract_package_hash_ptr,
            contract_package_hash_size,
            label_ptr,
            label_size,
        )
    };
    api_error::result_from(ret)
}

/// Add version to existing Package.
pub fn add_contract_version(
    package_hash: ContractPackageHash,
    entry_points: EntryPoints,
    named_keys: NamedKeys,
    message_topics: BTreeMap<String, MessageTopicOperation>,
) -> (ContractHash, EntityVersion) {
    // Retain the underscore as Wasm transpiliation requires it.
    let (package_hash_ptr, package_hash_size, _package_hash_bytes) =
        contract_api::to_ptr(package_hash);
    let (entry_points_ptr, entry_points_size, _entry_point_bytes) =
        contract_api::to_ptr(entry_points);
    let (named_keys_ptr, named_keys_size, _named_keys_bytes) = contract_api::to_ptr(named_keys);
    let (message_topics_ptr, message_topics_size, _message_topics) =
        contract_api::to_ptr(message_topics);

    let mut output_ptr = vec![0u8; 32];
    // let mut total_bytes: usize = 0;

    let mut entity_version: ContractVersion = 0;

    let ret = unsafe {
        ext_ffi::casper_add_contract_version_with_message_topics(
            package_hash_ptr,
            package_hash_size,
            &mut entity_version as *mut ContractVersion, // Fixed width
            entry_points_ptr,
            entry_points_size,
            named_keys_ptr,
            named_keys_size,
            message_topics_ptr,
            message_topics_size,
            output_ptr.as_mut_ptr(),
            output_ptr.len(),
            // &mut total_bytes as *mut usize,
        )
    };
    match api_error::result_from(ret) {
        Ok(_) => {}
        Err(e) => revert(e),
    }
    // output_ptr.truncate(32usize);
    let entity_hash: ContractHash = match bytesrepr::deserialize(output_ptr) {
        Ok(hash) => hash,
        Err(err) => panic!("{}", format!("{:?}", err)),
    };
    (entity_hash, entity_version)
}

/// Disables a specific version of a contract within the contract package identified by
/// `contract_package_hash`. Once disabled, the specified version will no longer be
/// callable by `call_versioned_contract`. Please note that the contract must have been
/// previously created using `create_contract` or `create_contract_package_at_hash`.
///
/// # Arguments
///
/// * `contract_package_hash` - The hash of the contract package containing the version to be
///   disabled.
/// * `contract_hash` - The hash of the specific contract version to be disabled.
///
/// # Errors
///
/// Returns a `Result` indicating success or an `ApiError` if the operation fails.
pub fn disable_contract_version(
    contract_package_hash: ContractPackageHash,
    contract_hash: ContractHash,
) -> Result<(), ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(contract_package_hash);
    let (contract_hash_ptr, contract_hash_size, _bytes2) = contract_api::to_ptr(contract_hash);

    let result = unsafe {
        ext_ffi::casper_disable_contract_version(
            contract_package_hash_ptr,
            contract_package_hash_size,
            contract_hash_ptr,
            contract_hash_size,
        )
    };

    api_error::result_from(result)
}

/// Enables a specific version of a contract from the contract package stored at the given hash.
/// Once enabled, that version of the contract becomes callable again by `call_versioned_contract`.
///
/// # Arguments
///
/// * `contract_package_hash` - The hash of the contract package containing the desired version.
/// * `contract_hash` - The hash of the specific contract version to be enabled.
///
/// # Errors
///
/// Returns a `Result` indicating success or an `ApiError` if the operation fails.
pub fn enable_contract_version(
    contract_package_hash: ContractPackageHash,
    contract_hash: ContractHash,
) -> Result<(), ApiError> {
    let (contract_package_hash_ptr, contract_package_hash_size, _bytes1) =
        contract_api::to_ptr(contract_package_hash);
    let (contract_hash_ptr, contract_hash_size, _bytes2) = contract_api::to_ptr(contract_hash);

    let result = unsafe {
        ext_ffi::casper_enable_contract_version(
            contract_package_hash_ptr,
            contract_package_hash_size,
            contract_hash_ptr,
            contract_hash_size,
        )
    };

    api_error::result_from(result)
}

/// Creates new [`URef`] that represents a seed for a dictionary partition of the global state and
/// puts it under named keys.
pub fn new_dictionary(dictionary_name: &str) -> Result<URef, ApiError> {
    if dictionary_name.is_empty() || runtime::has_key(dictionary_name) {
        return Err(ApiError::InvalidArgument);
    }

    let value_size = {
        let mut value_size = MaybeUninit::uninit();
        let ret = unsafe { ext_ffi::casper_new_dictionary(value_size.as_mut_ptr()) };
        api_error::result_from(ret)?;
        unsafe { value_size.assume_init() }
    };
    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    let uref: URef = bytesrepr::deserialize(value_bytes).unwrap_or_revert();
    runtime::put_key(dictionary_name, Key::from(uref));
    Ok(uref)
}

/// Retrieve `value` stored under `dictionary_item_key` in the dictionary accessed by
/// `dictionary_seed_uref`.
pub fn dictionary_get<V: CLTyped + FromBytes>(
    dictionary_seed_uref: URef,
    dictionary_item_key: &str,
) -> Result<Option<V>, bytesrepr::Error> {
    let (uref_ptr, uref_size, _bytes1) = contract_api::to_ptr(dictionary_seed_uref);
    let (dictionary_item_key_ptr, dictionary_item_key_size) =
        contract_api::dictionary_item_key_to_ptr(dictionary_item_key);

    if dictionary_item_key_size > DICTIONARY_ITEM_KEY_MAX_LENGTH {
        revert(ApiError::DictionaryItemKeyExceedsLength)
    }

    let value_size = {
        let mut value_size = MaybeUninit::uninit();
        let ret = unsafe {
            ext_ffi::casper_dictionary_get(
                uref_ptr,
                uref_size,
                dictionary_item_key_ptr,
                dictionary_item_key_size,
                value_size.as_mut_ptr(),
            )
        };
        match api_error::result_from(ret) {
            Ok(_) => unsafe { value_size.assume_init() },
            Err(ApiError::ValueNotFound) => return Ok(None),
            Err(e) => runtime::revert(e),
        }
    };

    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    Ok(Some(bytesrepr::deserialize(value_bytes)?))
}

/// Writes `value` under `dictionary_item_key` in the dictionary accessed by `dictionary_seed_uref`.
pub fn dictionary_put<V: CLTyped + ToBytes>(
    dictionary_seed_uref: URef,
    dictionary_item_key: &str,
    value: V,
) {
    let (uref_ptr, uref_size, _bytes1) = contract_api::to_ptr(dictionary_seed_uref);
    let (dictionary_item_key_ptr, dictionary_item_key_size) =
        contract_api::dictionary_item_key_to_ptr(dictionary_item_key);

    if dictionary_item_key_size > DICTIONARY_ITEM_KEY_MAX_LENGTH {
        revert(ApiError::DictionaryItemKeyExceedsLength)
    }

    let cl_value = CLValue::from_t(value).unwrap_or_revert();
    let (cl_value_ptr, cl_value_size, _bytes) = contract_api::to_ptr(cl_value);

    let result = unsafe {
        let ret = ext_ffi::casper_dictionary_put(
            uref_ptr,
            uref_size,
            dictionary_item_key_ptr,
            dictionary_item_key_size,
            cl_value_ptr,
            cl_value_size,
        );
        api_error::result_from(ret)
    };

    result.unwrap_or_revert()
}

/// Reads value under `dictionary_key` in the global state.
pub fn dictionary_read<T: CLTyped + FromBytes>(dictionary_key: Key) -> Result<Option<T>, ApiError> {
    if !dictionary_key.is_dictionary_key() {
        return Err(ApiError::UnexpectedKeyVariant);
    }

    let (key_ptr, key_size, _bytes) = contract_api::to_ptr(dictionary_key);

    let value_size = {
        let mut value_size = MaybeUninit::uninit();
        let ret =
            unsafe { ext_ffi::casper_dictionary_read(key_ptr, key_size, value_size.as_mut_ptr()) };
        match api_error::result_from(ret) {
            Ok(_) => unsafe { value_size.assume_init() },
            Err(ApiError::ValueNotFound) => return Ok(None),
            Err(e) => runtime::revert(e),
        }
    };

    let value_bytes = runtime::read_host_buffer(value_size).unwrap_or_revert();
    Ok(Some(bytesrepr::deserialize(value_bytes)?))
}

fn get_named_uref(name: &str) -> URef {
    match runtime::get_key(name).unwrap_or_revert_with(ApiError::GetKey) {
        Key::URef(uref) => uref,
        _ => revert(ApiError::UnexpectedKeyVariant),
    }
}

/// Gets a value out of a named dictionary.
pub fn named_dictionary_get<V: CLTyped + FromBytes>(
    dictionary_name: &str,
    dictionary_item_key: &str,
) -> Result<Option<V>, bytesrepr::Error> {
    dictionary_get(get_named_uref(dictionary_name), dictionary_item_key)
}

/// Writes a value in a named dictionary.
pub fn named_dictionary_put<V: CLTyped + ToBytes>(
    dictionary_name: &str,
    dictionary_item_key: &str,
    value: V,
) {
    dictionary_put(get_named_uref(dictionary_name), dictionary_item_key, value)
}