/* * Copyright (c) 2017 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @file parc_Buffer.h * @ingroup memory * @brief An indexable, linear buffer of bytes. * * A `PARCBuffer` is a linear, finite sequence of bytes. * The essential properties of a buffer are its content, its capacity, limit, and position: * * @htmlonly * * * * * * * * * * * * * * * icon_512x512 * * * Layer 1 * * Off * set * * * Position * Mark * * * Limit * * * Capacity * * * Array * * * * * * * * * * * * * * * @endhtmlonly * * * A buffer's capacity is the number of bytes it contains. * The capacity of a buffer is never negative and never changes. * * * A buffer's limit is the index of the first byte that should not be read or written. * A buffer's limit is never negative and is never greater than its capacity. * * * A buffer's position is a cursor to or index of the next byte to be read or written. * A buffer's position is never negative and is never greater than its limit. * * A PARCBuffer's capacity may be larger than the extent of data manipulated by the buffer. * The extent of the data manipulated by the buffer is manipulated via: * * {@link parcBuffer_Position}, * * {@link parcBuffer_SetPosition}, * * {@link parcBuffer_Limit}, * * {@link parcBuffer_SetLimit} and * * {@link parcBuffer_Flip}. * * Strictly speaking, these relations are always true: _0 <= mark <= position <= limit <= capacity_ * * The general model for use is to: * * Create a buffer using a form of {@link parcBuffer_Allocate} or {@link parcBuffer_Wrap}. * * Optionally insert data into the buffer via put operations, * ultimately setting the position at the end of the valid data. * * 'Flip' the buffer using the {@link parcBuffer_Flip} function to set the position to 0 and the limit at the end * of the valid data. * * Optionally get data from the buffer via one of the many get operations. * * Use {@link parcBuffer_Rewind} function to set the position to 0 again, leaving the limit at the end of the valid data. * * Data is placed into a `PARCBuffer` via `Put` functions, and retreived from the buffer via `Get` operations. * Both `Put` and `Get` perform their operations at the position of the buffer and update the position to the location of the * next element of data. * Both `Put` and `Get` operations have a full compliment of intrinsic data types that operate on data at * relative positions in the buffer. * * The function {@link parcBuffer_GetAtIndex} provides absolute index access to the buffer for bytes. * * * {@link parcBuffer_PutUint8}, * * {@link parcBuffer_PutUint16}, * * {@link parcBuffer_PutUint32}, * * {@link parcBuffer_PutUint64}, * * {@link parcBuffer_PutAtIndex} * * * {@link parcBuffer_GetUint8}, * * {@link parcBuffer_GetUint16}, * * {@link parcBuffer_GetUint32}, * * {@link parcBuffer_GetUint64}, * * {@link parcBuffer_GetAtIndex} * */ #ifndef libparc_parc_Buffer_h #define libparc_parc_Buffer_h typedef struct parc_buffer PARCBuffer; #include #include extern parcObjectDescriptor_Declaration(PARCBuffer); #ifdef PARCLibrary_DISABLE_VALIDATION # define parcBuffer_OptionalAssertValid(_instance_) #else # define parcBuffer_OptionalAssertValid(_instance_) parcBuffer_AssertValid(_instance_) #endif /** * Assert that an instance of `PARCBuffer` is valid. * * If the instance is not valid, terminate via `trapIllegalValue()` * * Valid means the internal state of the type is consistent with its required current or future behaviour. * This may include the validation of internal instances of types. * * @param [in] instance A pointer to a `PARCBuffer` instance. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(64); * * parcBuffer_AssertValid(array); * } * @endcode * @see parcBuffer_OptionalAssertValid */ void parcBuffer_AssertValid(const PARCBuffer *instance); /** * Determine if an instance of `PARCBuffer` is valid. * * * Valid means the internal state of the type is consistent with its required current or future behaviour. * This may include the validation of internal instances of types. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return true The instance is valid. * @return false The instance is not valid. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(64); * * if (parcBuffer_IsValid(buffer)) { * printf("Buffer is valid.\n"); * } * } * @endcode */ bool parcBuffer_IsValid(const PARCBuffer *buffer); /** * Create a new instance of `PARCBuffer` using dynamically allocated memory. * * The new buffer's position will be zero, * its limit will be set to `length`, * its mark will be undefined, * and each of its elements will be initialized to zero. * * If capacity is zero, the buffer contains no underlying byte array. * * @param [in] capacity The number of bytes to allocate. * * @return NULL Memory could not be allocated. * @return non-NULL A pointer to a `PARCBuffer` instance. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(64); * * parcBuffer_Release(&&buffer); * } * @endcode */ PARCBuffer *parcBuffer_Allocate(size_t capacity); /** * Create a new instance of `PARCBuffer` using using program supplied static memory (rather than allocated). * * The new buffer will be backed by the given array, @p array. * Modifications to the buffer will cause the array to be modified and vice versa. * * The new buffer's capacity will be @p arrayLength, * its initial position will be @p position , * the index of the first byte that should not be read or written will be @p limit, * and its mark will be undefined. * * In all cases, _0 <= position <= limit <= capacity_ * * Its backing array will be the given array, starting at index 0 of that array. * * @param [in] array A pointer to a memory array. * @param [in] arrayLength The length, in `uint8_t` units, of the memory array. * @param [in] position The initial value for the buffer's position. * @param [in] limit The initial value for the buffer's limit. * * @return A `PARCBuffer` pointer. * * Example: * @code * { * uint8_t array[64]; * * PARCBuffer *buffer = parcBuffer_Wrap(array, sizeof(array), 0, sizeof(array)); * * parcBuffer_Release(&buffer); * } * @endcode * * @see parcBuffer_Allocate * @see parcBuffer_Release */ PARCBuffer *parcBuffer_Wrap(void *array, size_t arrayLength, size_t position, size_t limit); /** * Create a new instance of `PARCBuffer` using referencing the given {@link PARCByteArray}. * * A reference to the `PARCByteArray` is acquired. * * The new buffer will be backed by the given `PARCByteArray`. * Modifications to the buffer will cause the array to be modified and vice versa. * * The new buffer's capacity will be @p arrayLength, * its initial position will be @p position , * the index of the first byte that should not be read or written will be @p limit, * and its mark will be undefined. * * In all cases, _0 <= position <= limit <= capacity_ * * The new buffer's * capacity will be the length of the `PARCByteArray`, * its initial position will be @p position , * the index of the first byte that should not be read or written will be @p limit, * and its mark will be undefined. * * @param [in] byteArray A pointer to a `PARCByteArray` instance. * @param [in] position The initial value for the buffer's position. * @param [in] limit The initial value for the buffer's limit which must be less than or equal to the PARCByteArray's capacity. * * @return A `PARCBuffer` pointer. * * Example: * @code * { * PARCByteArray *array = parcByteArray_Allocate(64); * * PARCBuffer *buffer = parcBuffer_WrapByteArray(array, 0, parcByteArray_Capacity(array)); * * parcBuffer_Release(&&buffer); * } * @endcode * * @see parcBuffer_Allocate * @see parcBuffer_Wrap */ PARCBuffer *parcBuffer_WrapByteArray(PARCByteArray *byteArray, size_t position, size_t limit); /** * Create a new instance of `PARCBuffer` wrapping the given null-terminated C string as its value. * * The new buffer's capacity will be the length of the string excluding the terminating nul character. * its initial position will be 0, * the index of the first byte that should not be read or written will be @p limit, * and its mark will be undefined. * * @param [in] string A pointer to a C-string to copy and then wrap. * * @return A `PARCBuffer` pointer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("Hello World"); * * parcBuffer_Release(&buffer); * } * @endcode * * @see parcBuffer_Allocate * @see parcBuffer_Wrap */ PARCBuffer *parcBuffer_WrapCString(char *string); /** * Create a new instance of a `PARCBuffer` copying the given null-terminated C string as its value. * * The new buffer's capacity will be the length of the string excluding the terminating nul character. * its initial position will be 0, * the index of the first byte that should not be read or written will be @p limit, * and its mark will be undefined. * * @param [in] string A pointer to C-string to copy and then wrap. * * @return A `PARCBuffer` pointer. * * Example: * @code * { * PARCByteArray *buffer = parcBuffer_AllocateCString("test string"); * * parcBUffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_AllocateCString(const char *string); /** * Create a `PARCBuffer` initalised with a copy of the contents of given byte array. * * The length must be non-negative (> 0) and the array pointer must not be NULL. * The contents of the given array are used to initialize the `PARCBuffer` instance, * and the size of the new instance is equal to the specified length (just wide enough to fit the array). * * @param [in] bytes A pointer to an array of bytes. * @param [in] length The number of bytes to copy to the `PARCBuffer`. * * @return A newly allocated `PARCBuffer` instance that must be freed via `parcBuffer_Release()`. * * Example: * @code * { * unsigned char array[] = { 1, 2, 3, 4, 5 }; * PARCBuffer *buffer = parcBuffer_CreateFromArray(array, sizeof(array)); * * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_CreateFromArray(const void *bytes, size_t length); /** * Parse a null-terminated hexadecimal string to create a new `PARCBuffer` instance. * * The hex string must be null-terminated so parsing is deterministic and correct. * The hex string parameter is not modified in any way. * The hex string must be an even length greater than zero. * * @param [in] hexString The hex string to parse. * * @return NULL The string could not be parsed * @return A new `PARCElasticBuffer` instance. * * Example: * @code * { * char *expected = "0123456789ABCDEF"; * PARCBuffer *buffer = parcBuffer_Flip(parcBuffer_ParseHexString(expected)); * printf("String: %s\n", parcBuffer_ToString(buffer)); * * parcBuffer_Release(buffer); * } * @endcode */ PARCBuffer *parcBuffer_ParseHexString(const char *hexString); /** * Increase or decrease the capacity of an existing PARCBuffer. * * If the new capacity is greater than the old capacity and the limit is currently set to the old capacity, * then set the new limit to the new capacity. * Otherwise, if the limit is not currently set to the capacity, then leave the limit unchanged. * * If the new capacity is less than the old capacity and the limit is currently set to the old capacity, * then set the new limit to the new capacity. * Otherwise, set the limit to the the lesser of the old limit or the new capacity. * If the limit is not currently set to the capacity, * the set the limit to the the lesser of the old limit or the new capacity. * * If the original mark exceeds the new limit, the new mark is invalidated and any subsequent * operation on the resulting `PARCBuffer` that requires the mark will abort until the mark * is set again via `parcBuffer_Mark`. * * If the original position of the buffer is beyond the new limit of the buffer, the position is set to the new limit. * * The contents of the old buffer are preserved from the origin to the new limit. * * This operation may induce a memory copy. * As a consequence, any `PARCBuffer` instances previously created via {@link parcBuffer_Slice} * refer to memory previously used by this `PARCBuffer`. * * A PARCBuffer originally created via any of the `parcBuffer_Wrap` forms, * may no longer refer to the original wrapped data. * * @param [in] buffer A pointer to a valid `PARCBuffer` instance. * @param [in] capacity The new capacity of `PARCBuffer` * * @return PARCBuffer A new `PARCBuffer` instance initialized with the contents of the given buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("Hello World"); * parcBuffer_Resize(buffer, 4); * * parcBuffer_Release(&buffer); * } * @endcode * * @see parcBuffer_Allocate * @see parcBuffer_Wrap */ PARCBuffer *parcBuffer_Resize(PARCBuffer *buffer, size_t capacity); /** * Increase the number of references to a `PARCBuffer`. * * Note that new `PARCBuffer` is not created, * only that the given `PARCBuffer` reference count is incremented. * Discard the reference by invoking `parcBuffer_Release`. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return The input `PARCBuffer` pointer. * * Example: * @code * { * PARCBuffer *x = parcBuffer_Allocate(10); * * PARCBuffer *x_2 = parcBuffer_Acquire(x); * * parcBuffer_Release(&x); * parcBuffer_Release(&x_2); * } * @endcode */ PARCBuffer *parcBuffer_Acquire(const PARCBuffer *buffer); /** * Release a previously acquired reference to the specified instance, * decrementing the reference count for the instance. * * The pointer to the instance is set to NULL as a side-effect of this function. * * If the invocation causes the last reference to the instance to be released, * the instance is deallocated and the instance's implementation will perform * additional cleanup and release other privately held references. * * @param [in,out] bufferPtr A pointer to a pointer to the instance to release. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * * parcBuffer_Release(&buffer); * } * @endcode */ void parcBuffer_Release(PARCBuffer **bufferPtr); /** * Returns this buffer's capacity. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return The given buffer's capacity. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * * size_t capacity = parcBuffer_Capacity(buffer); * * parcBuffer_Release(&capacity); * } * @endcode */ size_t parcBuffer_Capacity(const PARCBuffer *buffer); /** * Clear the given buffer restoring it to its initial state: * The position is set to zero, * the limit is set to the capacity, * and the mark is invalidated. * * The mark is made invalid and any subsequent operation on the resulting * `PARCBuffer` that requires the mark will abort until the mark * is set again via `parcBuffer_Mark`. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * * @return The value of @p buffer. * * Example: * @code * { * parcBuffer_Clear(buffer); * } * @endcode */ PARCBuffer *parcBuffer_Clear(PARCBuffer *buffer); /** * Determine if two `PARCBuffer` instances are equal. * * The following equivalence relations on non-null `PARCBuffer` instances are maintained: * * * It is reflexive: for any non-null reference value x, `parcBuffer_Equals(x, x)` must return true. * * * It is symmetric: for any non-null reference values x and y, `parcBuffer_Equals(x, y)` must return true if and only if * `parcBuffer_Equals(y x)` returns true. * * * It is transitive: for any non-null reference values x, y, and z, if * `parcBuffer_Equals(x, y)` returns true and * `parcBuffer_Equals(y, z)` returns true, * then `parcBuffer_Equals(x, z)` must return true. * * * It is consistent: for any non-null reference values x and y, multiple invocations of `parcBuffer_Equals(x, y)` * consistently return true or consistently return false. * * * For any non-null reference value x, `parcBuffer_Equals(x, NULL)` must return false. * * * @param [in] x A pointer to a `PARCBuffer` instance. * @param [in] y A pointer to a `PARCBuffer` instance. * * @return true `PARCBuffers` x and y are equal. * @return false `PARCBuffers` x and y are not equal. * * Example: * @code * { * PARCBuffer *bufferA = parcBuffer_Allocate(10); * PARCBuffer *bufferB = parcBuffer_Allocate(10); * * if (parcBuffer_Equals(bufferA, bufferB)) { * printf("Buffers are equal.\n"); * } else { * printf("Buffers are NOT equal.\n"); * } * * parcBuffer_Release(&bufferA); * parcBuffer_Release(&bufferB); * } * @endcode * * @see parcBuffer_HashCode */ bool parcBuffer_Equals(const PARCBuffer *x, const PARCBuffer *y); /** * Compares instance a with instance b for order. * * Returns a negative integer, zero, or a positive integer as instance * a is less than, equal to, or greater than instance b. * * The buffer's position, limit, and mark are not modified. * * @param [in] a A pointer to the first instance of `PARCBuffer`. * @param [in] b A pointer to the second instance of `PARCBuffer`. * * @return <0 Instance a is less than instance b. * @return 0 Instance a and instance b compare the same. * @return >0 Instance a is greater than instance b. * * Example: * @code * { * PARCBuffer *bufferA = parcBuffer_Allocate(10); * PARCBuffer *bufferB = parcBuffer_Allocate(10); * * if (parcBuffer_Compare(bufferA, bufferB) == 0) { * printf("Buffers are equal.\n"); * } * * parcBuffer_Release(&bufferA); * parcBuffer_Release(&bufferB); * } * @endcode * * @see parcBuffer_Equals */ int parcBuffer_Compare(const PARCBuffer *a, const PARCBuffer *b); /** * Return a pointer to the {@link PARCByteArray} that backs this buffer. * * If this `PARCBuffer` has a capacity of zero, * there is no array of bytes and this function returns NULL. * * Modifications to the contents of the `PARCByteArray` will visible to the given * `PARCBuffer` and vice-versa. * * The origin of the given `PARCBuffer` may not be the same as the origin of the underlying * `PARCByteArray`. * Use {@link parcBuffer_ArrayOffset} to obtain the origin of the given `PARCBuffer` * relative to the origin of the underlying `PARCByteArray` * * The caller must obtain its own reference to the `PARCByteArray` if it intends to store it elsewhere. * * Note: Many hard to find bugs can be caused by using this function. * Use the functions provided to manipulate the `PARCBuffer` and its contents. * * @param [in] buffer A `PARCBuffer` pointer. * * @return NULL There is no `PARCByteArray` backing the given `PARCBuffer` (no capacity). * @return non-NULL The pointer to the `PARCByteArray` for the given `PARCBuffer`. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * * PARCByteArray *array = parcBuffer_Array(buffer); * * parcBuffer_Release(&buffer); * } * @endcode * * @see parcByteArray_Acquire */ PARCByteArray *parcBuffer_Array(const PARCBuffer *buffer); /** * Create an independent copy the given `PARCBuffer` * * A new buffer is created as a complete copy of the original. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return NULL Memory could not be allocated. * @return non-NULL A pointer to a new `PARCBuffer` instance. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * PARCBuffer *copy = parcBuffer_Copy(buffer); * * parcBuffer_Release(©); * parcBuffer_Release(&buffer); * } * @endcode * */ PARCBuffer *parcBuffer_Copy(const PARCBuffer *buffer); /** * Creates a new buffer that shares the original buffer's content. * * The content of the new buffer will be that of this buffer. * Changes to the buffer's content will be visible in both buffers, * however the two buffers' position, limit, and mark values will be independent. * * The new buffer's capacity, limit, position, and mark values will be identical to those of the original buffer. * * @param [in] original The orignal PARCBuffer instance that will be duplicated. * * @return NULL Memory could not be allocated. * @return non-NULL A pointer to ta valid `PARCBuffer` instance. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_Duplicate(buffer2); * * parcBuffer_Release(&buffer); * parcBuffer_Release(&buffer2); * } * @endcode */ PARCBuffer *parcBuffer_Duplicate(const PARCBuffer *original); /** * Returns the offset within this buffer's backing {@link PARCByteArray} of the first element. * * Buffer position p corresponds to array index p + arrayOffset(). * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return `size_t` The offset within this `PARCBuffer`'s array of the first element of the buffer * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * size_t arrayOffset = parcBuffer_ArrayOffset(buffer); * // offset will be 0 since the contents of the buffer start at the beginning * * parcBuffer_Release(&buffer); * } * @endcode */ size_t parcBuffer_ArrayOffset(const PARCBuffer *buffer); /** * Rewinds this `PARCBuffer`: The position is set to zero and the mark is invalidated. * * The mark is made invalid and any subsequent operation on the resulting * `PARCBuffer` that requires the mark will abort until the mark * is set again via `parcBuffer_Mark`. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * * @return The given `PARCBuffer` pointer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * parcBuffer_Rewind(buffer); // bring it back to zero * * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_Rewind(PARCBuffer *buffer); /** * Resets the given `PARCBuffer`'s position to the previously-marked position. * * Invoking this method neither changes nor invalidates the mark's value. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * * @return The given `PARCBuffer` pointer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * buffer = parcBuffer_Reset(buffer); * * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_Reset(PARCBuffer *buffer); /** * Return the given `PARCBuffer`'s limit. * * A buffer's limit is the index of the first element that should not be read or written. * A buffer's limit is never negative and is never greater than its capacity. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return The given `PARCBuffer`'s limit. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * size_t limit = parcBuffer_Limit(buffer); * // limit will be 10 * * parcBuffer_Release(&buffer); * } * @endcode */ size_t parcBuffer_Limit(const PARCBuffer *buffer); /** * Sets this buffer's mark at its position. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * * @return The value of @p buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * parcBuffer_Mark(buffer); * // since the position was 0, the mark remains at 0 * * ... * * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_Mark(PARCBuffer *buffer); /** * Sets this `PARCBuffer`'s limit. * * If the position is larger than the new limit then it is set to the new limit. * * If the mark is defined and larger than the new limit then the mark is invalidated and * any subsequent operation that requires the mark will abort until the mark * is set again via `parcBuffer_Mark` * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * @param newLimit The new limit value; must be no larger than this `PARCBuffer`'s capacity. * * @return The given `PARCBuffer` pointer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint8(buffer, (uint8_t)'A'); * * parcBuffer_SetLimit(buffer, 8); * * size_t limit = parcBuffer_Limit(buffer); * size_t capacity = parcBuffer_Capacity(buffer); * // capacity is 10, limit is 8 * * ... * * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_SetLimit(PARCBuffer *buffer, size_t newLimit); /** * Return a pointer to buffer memory starting the buffer's current position. * * The @p length parameter must be less than or equal to the remaining bytes in the buffer * and has no effect on the return value, * except that if the buffer's position is equal to the limit, then this traps with OutOfBounds * * The current position of the buffer is advanced by @p length bytes. * It is acceptable for the @p length parameter to be zero, * thereby causing the current position to remain unchanged. * * This does not guarantee any particular memory alignment. * Therefore, it is possible to obtain a pointer to memory that cannot be accessed * as a native type because of CPU architecture alignment requirements. * * The function returns a pointer to contiguous memory within a `PARCBuffer`, * but does not acquire a reference to the `PARCBuffer` instance, * the underlying {@link PARCByteArray}, nor the actual memory array. * If the {@link PARCBuffer} or the underlying {@link PARCByteArray} is released finally, * the result from a previous call to `parcBuffer_Overlay` will point to undefined values. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * @param [in] length The number of bytes to advance the buffer's position. * * @return non-NULL A pointer to memory. * * Example: * @code * { * char *expected = "Hello World"; * struct timeval theTime = { .tv_sec = 123, .tv_usec = 456}; * * PARCBuffer *buffer = parcBuffer_Allocate(sizeof(uint16_t) + strlen(expected) + sizeof(theTime)); * * parcBuffer_PutUint16(buffer, strlen(expected)); * parcBuffer_PutUint8(buffer, expected, strlen(expected)); * parcBuffer_PutUint8(buffer, &theTime, sizeof(theTime)); * parcBuffer_Flip(); * * uint16_t length = parcBuffer_GetUint16(buffer); * char *actual = parcBuffer_Overlay(buffer, length); * struct timeval *tm = parcBuffer_Overlay(buffer, sizeof(struct timeval)); * } * @endcode */ void *parcBuffer_Overlay(PARCBuffer *buffer, size_t length); /** * Return the given `PARCBuffer`'s position. * * A buffer's position is the index of the next element to be read or written. * A buffer's position is never negative and is never greater than its limit. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * @return The given `PARCBuffer`'s position. * * Example: * @code * { * size_t currentPosition = parcBuffer_Position(buffer); * } * @endcode * * @see parcBuffer_SetPosition */ size_t parcBuffer_Position(const PARCBuffer *buffer); /** * Set the given `PARCBuffer`'s position. * * A buffer's position is the index of the next element to be read or written. * A buffer's position is never negative and is never greater than its limit. * * If the mark is defined and larger than the new position then the mark * is invalidated and any subsequent operation on the resulting * `PARCBuffer` that requires the mark will abort until the mark * is set again via `parcBuffer_Mark`. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * @param [in] newPosition The buffer's new position which must be less than or equal to the current limit. * * @return The given `PARCBuffer`'s position. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_SetPosition(buffer, 5); * parcBuffer_Remaining(buffer); // Returns 5. * } * @endcode * * @see parcBuffer_Limit */ PARCBuffer *parcBuffer_SetPosition(PARCBuffer *buffer, size_t newPosition); /** * Returns the number of elements between the current position and the limit. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return The number of elements remaining in this `PARCBuffer`. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_SetPosition(buffer, 5); * parcBuffer_Remaining(buffer); // Returns 5. * } * @endcode */ size_t parcBuffer_Remaining(const PARCBuffer *buffer); /** * Tells whether there are any elements between the current position and the limit. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return true The `PARCBuffer` contains at least one more element. * @return false The `PARCBuffer` does not contain any more elements. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_SetPosition(buffer, 5); * bool hasRemaining = parcBuffer_HasRemaining(buffer); // returns true since #remaining = 5 * } * @endcode */ bool parcBuffer_HasRemaining(const PARCBuffer *buffer); /** * Creates a new byte buffer whose content is a shared subsequence of this buffer's content. * * The content of the new buffer will start at this buffer's current position. * Changes to this buffer's content will be visible in the new buffer, * and vice versa; * the two buffers' position, limit, * and mark values will be independent. * * The new buffer's position will be zero, * its capacity and its limit will be the number of bytes remaining in this buffer, * and its mark will be undefined. * * @param [in] original A pointer to a `PARCBuffer` instance. * * @return non-NULL A pointer to a new `PARCBuffer` whose content is a shared subsequence of the original buffer's content. * @return NULL Memory could not be allocated. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_SetPosition(buffer, 5); * parcBuffer_SetLimit(buffer, 8); * * PARCBuffer *slice = parcBuffer_Slice(buffer); * // the slice will be the subset of bytes 5,6,7, and will * // have limit and capacity of 3 (= 8 - 5) * * ... * * parcBuffer_Release(&buffer); * parcBuffer_Release(&slice); * } * @endcode */ PARCBuffer *parcBuffer_Slice(const PARCBuffer *original); /** * Set the limit to the current position, * then set the position to zero. * If the mark is defined, it is invalidated. * * Any subsequent operation that requires the mark will abort until the mark * is set again via `parcBuffer_Mark`. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * * @return The same value as @p buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutByte(buffer, 'X'); * parcBuffer_Flip(buffer); * uint8_t actual = parcBuffer_GetUint8(buffer); * * ... * parcBuffer_Release(&buffer); * } * @endcode */ PARCBuffer *parcBuffer_Flip(PARCBuffer *buffer); /** * Get the single `uint8_t` at the index specified. * * The buffer's position is not modified. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * @param [in] index The index into the @p buffer to find the `uint8_t`. * * @return The `uint8_t` value at @p index. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutByte(buffer, 'X'); * uint8_t actual = parcBuffer_GetAtIndex(buffer, 0); * // actual == (uint8_t) 'X' * * ... * parcBuffer_Release(&buffer); * } * @endcode */ uint8_t parcBuffer_GetAtIndex(const PARCBuffer *buffer, size_t index); /** * Read the unsigned 8-bit value at the buffer's current position, * and then increment the position by 1. * * @param [in] buffer The pointer to a `PARCBuffer` instance containing the `uint8_t` value. * * @return The `uint8_t` at the buffer's current position * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutByte(buffer, 'X'); * parcBuffer_Flip(buffer); * uint8_t actual = parcBuffer_GetUint8(buffer); * * ... * parcBuffer_Release(&buffer); * } * @endcode * */ uint8_t parcBuffer_GetUint8(PARCBuffer *buffer); /** * Read the unsigned 16-bit value in network order at the buffer's current position, * and then increment the position by 2. * * @param [in,out] buffer The pointer to the `PARCBuffer` instance containing the value. * * @return The `uint16_t` at the buffer's current position. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * (buffer, 0x1234); * parcBuffer_Flip(buffer); * uint16_t actual = parcBuffer_GetUint16(buffer); * } * @endcode * * @see parcBuffer_Overlay */ uint16_t parcBuffer_GetUint16(PARCBuffer *buffer); /** * Read the unsigned 32-bit value in network order at the buffer's current position, * and then increment the position by the 4. * * @param [in,out] buffer The pointer to the instance of `PARCBuffer` containing the value. * * @return The `uint32_t` at the buffer's current position. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint32(buffer, 0x12345678); * parcBuffer_Flip(buffer); * uint32_t actual = parcBuffer_GetUint32(buffer); * } * @endcode * * @see parcBuffer_Overlay */ uint32_t parcBuffer_GetUint32(PARCBuffer *buffer); /** * Read the unsigned 64-bit value in network order at the buffer's current position, * and then increment the position by 8. * * @param [in,out] buffer The pointer to the instance of `PARCBuffer` containing the value. * * @return The `uint64_t` at the buffer's current position. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint64(buffer, 0x12345678); * parcBuffer_Flip(buffer); * uint64_t actual = parcBuffer_GetUint64(buffer); * } * @endcode * * @see parcBuffer_Overlay */ uint64_t parcBuffer_GetUint64(PARCBuffer *buffer); /** * Read an array of length bytes from the given PARCBuffer, copying them to an array. * * The buffer's position is incremented by @p length. * * @param [in,out] buffer The pointer to the instance of `PARCBuffer` containing the `uint8_t` value. * @param [in] length The number of `uint8_t` elements to get. * @param [in] array The `uint8_t` array to receive @p length bytes. * * @return A pointer to the given `PARCBuffer` instance * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(5); * parcBuffer_PutUint8(buffer, 'A'); * parcBuffer_PutUint8(buffer, 'B'); * parcBuffer_PutUint8(buffer, 'C'); * * uint8_t array[3]; * parcBuffer_GetBytes(buffer, 3, array); * // array[0] == 'A' * // array[1] == 'B' * // array[2] == 'C' * } * @endcode * * @see parcBuffer_Overlay */ PARCBuffer *parcBuffer_GetBytes(PARCBuffer *buffer, size_t length, uint8_t *array); /** * Insert an unsigned 8-bit value into the given `PARCBuffer` at the current position. * * Advance the current position by 1. * * @param [in,out] buffer A pointer to the `PARCBuffer` instance. * @param [in] value The value to be inserted into the`PARCBuffer` instance at the current position. * @return The `PARCBuffer` * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutByte(buffer, 'X'); * } * @endcode */ PARCBuffer *parcBuffer_PutUint8(PARCBuffer *buffer, uint8_t value); /** * Insert an unsigned 16-bit value into the given `PARCBuffer` at the current position, * in big-endian, network-byte-order. * * Advance the current position by 2. * * @param [in,out] buffer A pointer to the `PARCBuffer` instance. * @param [in] value The value to be inserted * @return The pointer to `PARCBuffer` * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint16(buffer, 0x1234); * } * @endcode */ PARCBuffer *parcBuffer_PutUint16(PARCBuffer *buffer, uint16_t value); /** * Insert an unsigned 32-bit value into the given `PARCBuffer` at the current position, * in big-endian, network-byte-order. * * Advance the current position by 4. * * @param [in,out] buffer A pointer to the `PARCBuffer` instance. * @param [in] value The value to be inserted * @return The `PARCBuffer` * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint32(buffer, 0x12345678); * } * @endcode */ PARCBuffer *parcBuffer_PutUint32(PARCBuffer *buffer, uint32_t value); /** * Insert an unsigned 64-bit value into the given `PARCBuffer` at the current position, * in big-endian, network-byte-order. * * Advance the current position by 8. * * @param [in,out] buffer A pointer to the `PARCBuffer` instance. * @param [in] value The value to be inserted * @return The `PARCBuffer` * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutUint64(buffer, 0x1234); * } * @endcode */ PARCBuffer *parcBuffer_PutUint64(PARCBuffer *buffer, uint64_t value); /** * Insert unsigned 8-bit value to the given `PARCBuffer` at given index. * * The buffer's position is unchanged. * * @param [in,out] buffer A pointer to the `PARCBuffer` instance. * @param [in] index The index at which to insert @p value * @param [in] value The value to be inserted * * @return The value of @p buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * parcBuffer_PutAtIndex(buffer, 3, 'X'); * } * @endcode */ PARCBuffer *parcBuffer_PutAtIndex(PARCBuffer *buffer, size_t index, uint8_t value); /** * Copy `arrayLength` bytes from the given array into the `PARCBuffer`. * * The position is incremented by `arrayLength` * * @param [in] buffer A pointer to the `PARCBuffer` instance. * @param [in] arrayLength The number of bytes to copy into the buffer. * @param [in] array A pointer to the array of bytes. * * @return The value of @p buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(5); * * uint8_t array[3]; * array[0] = 'A'; * array[1] = 'B'; * array[2] = 'C'; * * parcBuffer_PutArray(buffer, 3, array); * // the buffer will now contain ['A','B','C'] at indices 0,1,2 * } * @endcode */ PARCBuffer *parcBuffer_PutArray(PARCBuffer *buffer, size_t arrayLength, const uint8_t *array); /** * Copy the contents of the given nul-terminated C string into a PARCBuffer, including the terminating nul byte. * * The position is incremented by the length of the string plus 1. * * @param [in] buffer A pointer to the `PARCBuffer` instance. * @param [in] string A pointer to nul-terminated C string. * * @return The value of @p buffer. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(5); * * char *string = "ABC"; * * parcBuffer_PutCString(buffer, string); * // the buffer will now contain ['A','B','C', 0] at indices 0, 1, 2, and 3 * } * @endcode */ PARCBuffer *parcBuffer_PutCString(PARCBuffer *buffer, const char *string); /** * Put the contents of a `PARCBuffer` into another. * * @param [in] buffer A pointer to the destination `PARCBuffer` instance. * @param [in] source A pointer to the source `PARCBuffer` instance. * * @return The value of @p result. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * PARCBuffer *insertee = parcBuffer_AllocateCString("Hello"); * parcBuffer_PutBuffer(buffer, insertee); * // buffer will now contain "Hello" in the first 5 byte indices * } * @endcode */ PARCBuffer *parcBuffer_PutBuffer(PARCBuffer *buffer, const PARCBuffer *source); /** * Returns a hash code value for the given instance. * * The hash code of a `PARCBuffer` depends only upon its remaining elements from the current position to the limit. * * Because `PARCBuffer` hash codes are content-dependent, be careful when using them as keys in `PARCHashMap` * and other similar data structures unless it is known that their contents will not change. * * The general contract of `HashCode` is: * * Whenever it is invoked on the same instance more than once during an execution of an application, * the `HashCode` function must consistently return the same value, * provided no information used in a corresponding {@link parcByteArray_Equals} * comparisons on the instance is modified. * * This value need not remain consistent from one execution of an application to another execution of the same application. * If two instances are equal according to the {@link parcByteArray_Equals} method, * then calling the {@link parcBuffer_HashCode} method on each of the two instances must produce the same integer result. * * It is not required that if two instances are unequal according to the {@link parcBuffer_Equals} function, * then calling the `parcBuffer_HashCode` * method on each of the two objects must produce distinct integer results. * * @param [in] buffer A pointer to the `PARCBuffer` instance. * * @return The hashcode for the given instance. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Allocate(10); * uint32_t hashValue = parcBuffer_HashCode(buffer); * parcBuffer_Release(&buffer); * } * @endcode * * @see parcByteArray_HashCode */ PARCHashCode parcBuffer_HashCode(const PARCBuffer *buffer); /** * Return the position of the first `uint8_t` value that matches the given byte. * * If the value does not exist between the current position and the limit, * return `SIZE_MAX` (). * * @param [in] buffer A pointer to a `PARCBuffer` instance. * @param [in] byte The byte to search for within the buffer. * * @return The index of the first byte equal to `byte`, or `SIZE_MAX` () * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_Wrap("Hello World", 10, 0, 10); * * size_t ePosition = parcBuffer_FindUint8(buffer, 'e'); * * // ePosition is equal to 1. * * size_t xPosition = parcBuffer_FindUint8(buffer, 'x'); * * // ePosition is equal to SIZE_MAX. * } * @endcode */ size_t parcBuffer_FindUint8(const PARCBuffer *buffer, uint8_t byte); /** * Produce a null-terminated string representation of the specified `PARCBuffer` * from the current position to the limit. * The buffer's position is not changed. * * The result must be freed by the caller via {@link parcMemory_Deallocate}. * * @param [in] buffer A pointer to the instance. * * @return NULL Cannot allocate memory. * @return non-NULL A pointer to an allocated, null-terminated C string that must be deallocated via {@link parcMemory_Deallocate}. * * Example: * @code * { * char *helloWorld = "Hello World"; * PARCBuffer *instance = parcBuffer_Wrap(helloWorld, strlen(helloWorld), 0, strlen(helloWorld)); * * char *string = parcBuffer_ToString(instance); * * if (string != NULL) { * printf("Hello: %s\n", string); * parcMemory_Deallocate((void **)&string); * } else { * printf("Cannot allocate memory\n"); * } * * parcBuffer_Release(&instance); * } * @endcode * * @see parcBuffer_Display */ char *parcBuffer_ToString(const PARCBuffer *buffer); /** * Print a human readable representation of the given `PARCBuffer`. * * @param [in] indentation The level of indentation to use to pretty-print the output. * @param [in] buffer A pointer to the instance to display. * * Example: * @code * { * PARCBuffer *instance = parcBuffer_Create(); * * parcBuffer_Display(instance, 0); * * parcBuffer_Release(&instance); * } * @endcode */ void parcBuffer_Display(const PARCBuffer *buffer, int indentation); /** * Return a null-terminated string containing the hex-byte representation of the given `PARCBuffer`. * * The result must be freed by the caller via `parcMemory_Deallocate()`. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return NULL Cannot allocate memory. * @return non-NULL A pointer to an allocated, null-terminated C string that must be deallocated via {@link parcMemory_Deallocate}. * * Example: * @code * { * PARCBuffer *instance = parcBuffer_Create(); * * char *hexString = parcBuffer_ToHexString(instance); * parcMemory_Deallocate((void **)&hexString); * * parcBuffer_Release(&instance); * } * @endcode * * @see parcMemory_Deallocate */ char *parcBuffer_ToHexString(const PARCBuffer *buffer); /** * Advance the position of the given buffer to the first byte that is not in the array @p bytesToSkipOver. * * The position will not exceed the PARCBuffer's limit. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * @param [in] length Length of the byte array that includes skip bytes * @param [in] bytesToSkipOver A null-terminated array of bytes to skip. * * @return true The `PARCBuffer`'s position was updated. * @return false The `PARCBuffer`'s position reached the limit. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("Hello World"); * uint8_t skipOverBytes[] = { 'H', 0 }; * * bool actual = parcBuffer_SkipOver(buffer, 1, skipOverBytes); * // the buffer position will now be 1, as it skipped over the 'H' byte in the array * // actual will be true * } * @endcode * * @see parcBuffer_SkipTo */ bool parcBuffer_SkipOver(PARCBuffer *buffer, size_t length, const uint8_t *bytesToSkipOver); /** * Advance the position of the given buffer to the first byte that is in the array @p bytesToSkipTo. * * The position will not exceed the PARCBuffer's limit. * * @param [in,out] buffer A pointer to a `PARCBuffer` instance. * @param [in] length Length of the byte array that includes skip bytes * @param [in] bytesToSkipTo A null-terminated array of bytes to find. * * @return true The PARCBuffer's position is at the first byte matched. * @return false The PARCBuffer's position reached the limit. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("Hello World"); * uint8_t skipOverBytes[] = { 'l', 0 }; * * bool actual = parcBuffer_SkipTo(buffer, 1, skipOverBytes); * // the buffer position will now be set to the index of the first 'l' byte in the underlying array * // actual will be true * } * @endcode * * @see parcBuffer_SkipOver */ bool parcBuffer_SkipTo(PARCBuffer *buffer, size_t length, const uint8_t *bytesToSkipTo); /** * Return the byte at the given `PARCBuffers'` current position, without modifying the position. * * @param [in] buffer A pointer to a `PARCBuffer` instance. * * @return The byte at the given `PARCBuffers'` current position * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_AllocateCString("Hello"); * uint8_t byte = parcBuffer_PeekByte(1); * // byte == (uint8_t) 'e'; * } * @endcode */ uint8_t parcBuffer_PeekByte(const PARCBuffer *buffer); /** * Parse an ASCII representation of a hexadecimal number in the given `PARCBuffer` * * The number may be prefixed with the characters '0', 'x'. * The buffer's position will be left at the first non-parsable character. * * Overflow is not checked. * * @param [in] buffer A pointer to a valid `PARCBuffer` instance. * * @return A uint64_t of the hexadecimal number. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("0x10"); * uint64_t value = parcBuffer_ParseHexNumber(buffer); * * parcBuffer_Release(&buffer); * } * @endcode */ uint64_t parcBuffer_ParseHexNumber(PARCBuffer *buffer); /** * Parse an ASCII representation of a unsigned decimal number in the given `PARCBuffer` * * The buffer's position will be left at the first non-parsable character. * * Overflow is not checked. * * @param [in] buffer A pointer to a valid `PARCBuffer` instance. * * @return A uint64_t of the decimal number. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("100"); * uint64_t value = parcBuffer_ParseDecimalNumber(buffer); * * parcBuffer_Release(&buffer); * } * @endcode */ uint64_t parcBuffer_ParseDecimalNumber(PARCBuffer *buffer); /** * Parse an ASCII representation of a unsigned decimal number or a hexadecimal number in the given `PARCBuffer` * * The buffer's position will be left at the first non-parsable character. * * Overflow is not checked. * * @param [in] buffer A pointer to a valid `PARCBuffer` instance. * * @return A uint64_t of the number. * * Example: * @code * { * PARCBuffer *buffer = parcBuffer_WrapCString("100"); * uint64_t value = parcBuffer_ParseNumeric(buffer); * * parcBuffer_Release(&buffer); * } * @endcode */ uint64_t parcBuffer_ParseNumeric(PARCBuffer *buffer); #endif // libparc_parc_Buffer_h