mirror-ghostty/include/ghostty/vt.h

456 lines
17 KiB
C

/**
* @file vt.h
*
* libghostty-vt - Virtual terminal sequence parsing library
*
* This library provides functionality for parsing and handling terminal
* escape sequences as well as maintaining terminal state such as styles,
* cursor position, screen, scrollback, and more.
*
* WARNING: This is an incomplete, work-in-progress API. It is not yet
* stable and is definitely going to change.
*/
/**
* @mainpage libghostty-vt - Virtual Terminal Sequence Parser
*
* libghostty-vt is a C library which implements a modern terminal emulator,
* extracted from the [Ghostty](https://ghostty.org) terminal emulator.
*
* libghostty-vt contains the logic for handling the core parts of a terminal
* emulator: parsing terminal escape sequences and maintaining terminal state.
* It can handle scrollback, line wrapping, reflow on resize, and more.
*
* @warning This library is currently in development and the API is not yet stable.
* Breaking changes are expected in future versions. Use with caution in production code.
*
* @section groups_sec API Reference
*
* The API is organized into the following groups:
* - @ref osc "OSC Parser" - Parse OSC (Operating System Command) sequences
* - @ref allocator "Memory Management" - Memory management and custom allocators
*
*/
#ifndef GHOSTTY_VT_H
#define GHOSTTY_VT_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
//-------------------------------------------------------------------
// Types
/**
* Opaque handle to an OSC parser instance.
*
* This handle represents an OSC (Operating System Command) parser that can
* be used to parse the contents of OSC sequences. This isn't a full VT
* parser; it is only the OSC parser component. This is useful if you have
* a parser already and want to only extract and handle OSC sequences.
*
* @ingroup osc
*/
typedef struct GhosttyOscParser *GhosttyOscParser;
/**
* Opaque handle to a single OSC command.
*
* This handle represents a parsed OSC (Operating System Command) command.
* The command can be queried for its type and associated data using
* `ghostty_osc_command_type` and `ghostty_osc_command_data`.
*
* @ingroup osc
*/
typedef struct GhosttyOscCommand *GhosttyOscCommand;
/**
* Result codes for libghostty-vt operations.
*/
typedef enum {
/** Operation completed successfully */
GHOSTTY_SUCCESS = 0,
/** Operation failed due to failed allocation */
GHOSTTY_OUT_OF_MEMORY = -1,
} GhosttyResult;
/**
* OSC command types.
*
* @ingroup osc
*/
typedef enum {
GHOSTTY_OSC_COMMAND_INVALID = 0,
GHOSTTY_OSC_COMMAND_CHANGE_WINDOW_TITLE = 1,
GHOSTTY_OSC_COMMAND_CHANGE_WINDOW_ICON = 2,
GHOSTTY_OSC_COMMAND_PROMPT_START = 3,
GHOSTTY_OSC_COMMAND_PROMPT_END = 4,
GHOSTTY_OSC_COMMAND_END_OF_INPUT = 5,
GHOSTTY_OSC_COMMAND_END_OF_COMMAND = 6,
GHOSTTY_OSC_COMMAND_CLIPBOARD_CONTENTS = 7,
GHOSTTY_OSC_COMMAND_REPORT_PWD = 8,
GHOSTTY_OSC_COMMAND_MOUSE_SHAPE = 9,
GHOSTTY_OSC_COMMAND_COLOR_OPERATION = 10,
GHOSTTY_OSC_COMMAND_KITTY_COLOR_PROTOCOL = 11,
GHOSTTY_OSC_COMMAND_SHOW_DESKTOP_NOTIFICATION = 12,
GHOSTTY_OSC_COMMAND_HYPERLINK_START = 13,
GHOSTTY_OSC_COMMAND_HYPERLINK_END = 14,
GHOSTTY_OSC_COMMAND_CONEMU_SLEEP = 15,
GHOSTTY_OSC_COMMAND_CONEMU_SHOW_MESSAGE_BOX = 16,
GHOSTTY_OSC_COMMAND_CONEMU_CHANGE_TAB_TITLE = 17,
GHOSTTY_OSC_COMMAND_CONEMU_PROGRESS_REPORT = 18,
GHOSTTY_OSC_COMMAND_CONEMU_WAIT_INPUT = 19,
GHOSTTY_OSC_COMMAND_CONEMU_GUIMACRO = 20,
} GhosttyOscCommandType;
/**
* OSC command data types.
*
* These values specify what type of data to extract from an OSC command
* using `ghostty_osc_command_data`.
*
* @ingroup osc
*/
typedef enum {
/** Invalid data type. Never results in any data extraction. */
GHOSTTY_OSC_DATA_INVALID = 0,
/**
* Window title string data.
*
* Valid for: GHOSTTY_OSC_COMMAND_CHANGE_WINDOW_TITLE
*
* Output type: const char ** (pointer to null-terminated string)
*
* Lifetime: Valid until the next call to any ghostty_osc_* function with
* the same parser instance. Memory is owned by the parser.
*/
GHOSTTY_OSC_DATA_CHANGE_WINDOW_TITLE_STR = 1,
} GhosttyOscCommandData;
//-------------------------------------------------------------------
// Allocator Interface
/** @defgroup allocator Memory Management
*
* libghostty-vt does require memory allocation for various operations,
* but is resilient to allocation failures and will gracefully handle
* out-of-memory situations by returning error codes.
*
* The exact memory management semantics are documented in the relevant
* functions and data structures.
*
* libghostty-vt uses explicit memory allocation via an allocator
* interface provided by GhosttyAllocator. The interface is based on the
* [Zig](https://ziglang.org) allocator interface, since this has been
* shown to be a flexible and powerful interface in practice and enables
* a wide variety of allocation strategies.
*
* **For the common case, you can pass NULL as the allocator for any
* function that accepts one,** and libghostty will use a default allocator.
* The default allocator will be libc malloc/free if libc is linked.
* Otherwise, a custom allocator is used (currently Zig's SMP allocator)
* that doesn't require any external dependencies.
*
* ## Basic Usage
*
* For simple use cases, you can ignore this interface entirely by passing NULL
* as the allocator parameter to functions that accept one. This will use the
* default allocator (typically libc malloc/free, if libc is linked, but
* we provide our own default allocator if libc isn't linked).
*
* To use a custom allocator:
* 1. Implement the GhosttyAllocatorVtable function pointers
* 2. Create a GhosttyAllocator struct with your vtable and context
* 3. Pass the allocator to functions that accept one
*
* @{
*/
/**
* Function table for custom memory allocator operations.
*
* This vtable defines the interface for a custom memory allocator. All
* function pointers must be valid and non-NULL.
*
* @ingroup allocator
*
* If you're not going to use a custom allocator, you can ignore all of
* this. All functions that take an allocator pointer allow NULL to use a
* default allocator.
*
* The interface is based on the Zig allocator interface. I'll say up front
* that it is easy to look at this interface and think "wow, this is really
* overcomplicated". The reason for this complexity is well thought out by
* the Zig folks, and it enables a diverse set of allocation strategies
* as shown by the Zig ecosystem. As a consolation, please note that many
* of the arguments are only needed for advanced use cases and can be
* safely ignored in simple implementations. For example, if you look at
* the Zig implementation of the libc allocator in `lib/std/heap.zig`
* (search for CAllocator), you'll see it is very simple.
*
* We chose to align with the Zig allocator interface because:
*
* 1. It is a proven interface that serves a wide variety of use cases
* in the real world via the Zig ecosystem. It's shown to work.
*
* 2. Our core implementation itself is Zig, and this lets us very
* cheaply and easily convert between C and Zig allocators.
*
* NOTE(mitchellh): In the future, we can have default implementations of
* resize/remap and allow those to be null.
*/
typedef struct {
/**
* Return a pointer to `len` bytes with specified `alignment`, or return
* `NULL` indicating the allocation failed.
*
* @param ctx The allocator context
* @param len Number of bytes to allocate
* @param alignment Required alignment for the allocation. Guaranteed to
* be a power of two between 1 and 16 inclusive.
* @param ret_addr First return address of the allocation call stack (0 if not provided)
* @return Pointer to allocated memory, or NULL if allocation failed
*/
void* (*alloc)(void *ctx, size_t len, uint8_t alignment, uintptr_t ret_addr);
/**
* Attempt to expand or shrink memory in place.
*
* `memory_len` must equal the length requested from the most recent
* successful call to `alloc`, `resize`, or `remap`. `alignment` must
* equal the same value that was passed as the `alignment` parameter to
* the original `alloc` call.
*
* `new_len` must be greater than zero.
*
* @param ctx The allocator context
* @param memory Pointer to the memory block to resize
* @param memory_len Current size of the memory block
* @param alignment Alignment (must match original allocation)
* @param new_len New requested size
* @param ret_addr First return address of the allocation call stack (0 if not provided)
* @return true if resize was successful in-place, false if relocation would be required
*/
bool (*resize)(void *ctx, void *memory, size_t memory_len, uint8_t alignment, size_t new_len, uintptr_t ret_addr);
/**
* Attempt to expand or shrink memory, allowing relocation.
*
* `memory_len` must equal the length requested from the most recent
* successful call to `alloc`, `resize`, or `remap`. `alignment` must
* equal the same value that was passed as the `alignment` parameter to
* the original `alloc` call.
*
* A non-`NULL` return value indicates the resize was successful. The
* allocation may have same address, or may have been relocated. In either
* case, the allocation now has size of `new_len`. A `NULL` return value
* indicates that the resize would be equivalent to allocating new memory,
* copying the bytes from the old memory, and then freeing the old memory.
* In such case, it is more efficient for the caller to perform the copy.
*
* `new_len` must be greater than zero.
*
* @param ctx The allocator context
* @param memory Pointer to the memory block to remap
* @param memory_len Current size of the memory block
* @param alignment Alignment (must match original allocation)
* @param new_len New requested size
* @param ret_addr First return address of the allocation call stack (0 if not provided)
* @return Pointer to resized memory (may be relocated), or NULL if manual copy is needed
*/
void* (*remap)(void *ctx, void *memory, size_t memory_len, uint8_t alignment, size_t new_len, uintptr_t ret_addr);
/**
* Free and invalidate a region of memory.
*
* `memory_len` must equal the length requested from the most recent
* successful call to `alloc`, `resize`, or `remap`. `alignment` must
* equal the same value that was passed as the `alignment` parameter to
* the original `alloc` call.
*
* @param ctx The allocator context
* @param memory Pointer to the memory block to free
* @param memory_len Size of the memory block
* @param alignment Alignment (must match original allocation)
* @param ret_addr First return address of the allocation call stack (0 if not provided)
*/
void (*free)(void *ctx, void *memory, size_t memory_len, uint8_t alignment, uintptr_t ret_addr);
} GhosttyAllocatorVtable;
/**
* Custom memory allocator.
*
* For functions that take an allocator pointer, a NULL pointer indicates
* that the default allocator should be used. The default allocator will
* be libc malloc/free if we're linking to libc. If libc isn't linked,
* a custom allocator is used (currently Zig's SMP allocator).
*
* @ingroup allocator
*
* Usage example:
* @code
* GhosttyAllocator allocator = {
* .vtable = &my_allocator_vtable,
* .ctx = my_allocator_state
* };
* @endcode
*/
typedef struct {
/**
* Opaque context pointer passed to all vtable functions.
* This allows the allocator implementation to maintain state
* or reference external resources needed for memory management.
*/
void *ctx;
/**
* Pointer to the allocator's vtable containing function pointers
* for memory operations (alloc, resize, remap, free).
*/
const GhosttyAllocatorVtable *vtable;
} GhosttyAllocator;
/** @} */ // end of allocator group
//-------------------------------------------------------------------
// Functions
/** @defgroup osc OSC Parser
*
* OSC (Operating System Command) sequence parser and command handling.
*
* The parser operates in a streaming fashion, processing input byte-by-byte
* to handle OSC sequences that may arrive in fragments across multiple reads.
* This interface makes it easy to integrate into most environments and avoids
* over-allocating buffers.
*
* ## Basic Usage
*
* 1. Create a parser instance with ghostty_osc_new()
* 2. Feed bytes to the parser using ghostty_osc_next()
* 3. Finalize parsing with ghostty_osc_end() to get the command
* 4. Query command type and extract data using ghostty_osc_command_type()
* and ghostty_osc_command_data()
* 5. Free the parser with ghostty_osc_free() when done
*
* @{
*/
/**
* Create a new OSC parser instance.
*
* Creates a new OSC (Operating System Command) parser using the provided
* allocator. The parser must be freed using ghostty_vt_osc_free() when
* no longer needed.
*
* @param allocator Pointer to the allocator to use for memory management, or NULL to use the default allocator
* @param parser Pointer to store the created parser handle
* @return GHOSTTY_SUCCESS on success, or an error code on failure
*/
GhosttyResult ghostty_osc_new(const GhosttyAllocator *allocator, GhosttyOscParser *parser);
/**
* Free an OSC parser instance.
*
* Releases all resources associated with the OSC parser. After this call,
* the parser handle becomes invalid and must not be used.
*
* @param parser The parser handle to free (may be NULL)
*/
void ghostty_osc_free(GhosttyOscParser parser);
/**
* Reset an OSC parser instance to its initial state.
*
* Resets the parser state, clearing any partially parsed OSC sequences
* and returning the parser to its initial state. This is useful for
* reusing a parser instance or recovering from parse errors.
*
* @param parser The parser handle to reset, must not be null.
*/
void ghostty_osc_reset(GhosttyOscParser parser);
/**
* Parse the next byte in an OSC sequence.
*
* Processes a single byte as part of an OSC sequence. The parser maintains
* internal state to track the progress through the sequence. Call this
* function for each byte in the sequence data.
*
* When finished pumping the parser with bytes, call ghostty_osc_end
* to get the final result.
*
* @param parser The parser handle, must not be null.
* @param byte The next byte to parse
*/
void ghostty_osc_next(GhosttyOscParser parser, uint8_t byte);
/**
* Finalize OSC parsing and retrieve the parsed command.
*
* Call this function after feeding all bytes of an OSC sequence to the parser
* using ghostty_osc_next() with the exception of the terminating character
* (ESC or ST). This function finalizes the parsing process and returns the
* parsed OSC command.
*
* The return value is never NULL. Invalid commands will return a command
* with type GHOSTTY_OSC_COMMAND_INVALID.
*
* The terminator parameter specifies the byte that terminated the OSC sequence
* (typically 0x07 for BEL or 0x5C for ST after ESC). This information is
* preserved in the parsed command so that responses can use the same terminator
* format for better compatibility with the calling program. For commands that
* do not require a response, this parameter is ignored and the resulting
* command will not retain the terminator information.
*
* The returned command handle is valid until the next call to any
* `ghostty_osc_*` function with the same parser instance with the exception
* of command introspection functions such as `ghostty_osc_command_type`.
*
* @param parser The parser handle, must not be null.
* @param terminator The terminating byte of the OSC sequence (0x07 for BEL, 0x5C for ST)
* @return Handle to the parsed OSC command
*/
GhosttyOscCommand ghostty_osc_end(GhosttyOscParser parser, uint8_t terminator);
/**
* Get the type of an OSC command.
*
* Returns the type identifier for the given OSC command. This can be used
* to determine what kind of command was parsed and what data might be
* available from it.
*
* @param command The OSC command handle to query (may be NULL)
* @return The command type, or GHOSTTY_OSC_COMMAND_INVALID if command is NULL
*/
GhosttyOscCommandType ghostty_osc_command_type(GhosttyOscCommand command);
/**
* Extract data from an OSC command.
*
* Extracts typed data from the given OSC command based on the specified
* data type. The output pointer must be of the appropriate type for the
* requested data kind. Valid command types, output types, and memory
* safety information are documented in the `GhosttyOscCommandData` enum.
*
* @param command The OSC command handle to query (may be NULL)
* @param data The type of data to extract
* @param out Pointer to store the extracted data (type depends on data parameter)
* @return true if data extraction was successful, false otherwise
*/
bool ghostty_osc_command_data(GhosttyOscCommand command, GhosttyOscCommandData data, void *out);
/** @} */ // end of osc group
#ifdef __cplusplus
}
#endif
#endif /* GHOSTTY_VT_H */