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HTML Tidy
5.4.0
The HTACG Tidy HTML Project
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HTML Tidy
5.4.0
The HTACG Tidy HTML Project
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Tidy uses a user provided allocator for all memory allocations. More...
Data Structures | |
| struct | _TidyAllocator |
| An allocator. More... | |
| struct | _TidyAllocatorVtbl |
| An allocator's function table. More... | |
Typedefs | |
| typedef struct _TidyAllocator | TidyAllocator |
| The allocator. More... | |
| typedef struct _TidyAllocatorVtbl | TidyAllocatorVtbl |
| The allocators function table. More... | |
| typedef void(TIDY_CALL * | TidyFree) (void *buf) |
| Callback for "free" replacement. More... | |
| typedef void *(TIDY_CALL * | TidyMalloc) (size_t len) |
| Callback for "malloc" replacement. More... | |
| typedef void(TIDY_CALL * | TidyPanic) (ctmbstr mssg) |
| Callback for "out of memory" panic state. More... | |
| typedef void *(TIDY_CALL * | TidyRealloc) (void *buf, size_t len) |
| Callback for "realloc" replacement. More... | |
Functions | |
| Bool TIDY_CALL | tidySetFreeCall (TidyFree ffree) |
| Give Tidy a free() replacement. More... | |
| Bool TIDY_CALL | tidySetMallocCall (TidyMalloc fmalloc) |
| Give Tidy a malloc() replacement. More... | |
| Bool TIDY_CALL | tidySetPanicCall (TidyPanic fpanic) |
| Give Tidy an "out of memory" handler. More... | |
| Bool TIDY_CALL | tidySetReallocCall (TidyRealloc frealloc) |
| Give Tidy a realloc() replacement. More... | |
Tidy uses a user provided allocator for all memory allocations.
If this allocator is not provided, then a default allocator is used which simply wraps standard C malloc/free calls. These wrappers call the panic function upon any failure. The default panic function prints an out of memory message to stderr, and calls exit(2).
For applications in which it is unacceptable to abort in the case of memory allocation, then the panic function can be replaced with one which longjmps() out of the tidy code. For this to clean up completely, you should be careful not to use any tidy methods that open files as these will not be closed before panic() is called.
TODO: associate file handles with tidyDoc and ensure that tidyDocRelease() can close them all.
Calling the withAllocator() family ( tidyCreateWithAllocator, tidyBufInitWithAllocator, tidyBufAllocWithAllocator) allow settings custom allocators).
All parts of the document use the same allocator. Calls that require a user provided buffer can optionally use a different allocator.
For reference in designing a plug-in allocator, most allocations made by tidy are less than 100 bytes, corresponding to attribute names/values, etc.
There is also an additional class of much larger allocations which are where most of the data from the lexer is stored. (It is not currently possible to use a separate allocator for the lexer, this would be a useful extension).
In general, approximately 1/3rd of the memory used by tidy is freed during the parse, so if memory usage is an issue then an allocator that can reuse this memory is a good idea.
| struct _TidyAllocator |
An allocator.
To create your own allocator, do something like the following:
Although this looks slightly long winded, the advantage is that to create a custom allocator you simply need to set the vtbl pointer correctly. The vtbl itself can reside in static/global data, and hence does not need to be initialised each time an allocator is created, and furthermore the memory is shared amongst all created allocators.
| Data Fields | ||
|---|---|---|
| const TidyAllocatorVtbl * | vtbl | |
| struct _TidyAllocatorVtbl |
An allocator's function table.
All functions here must be provided.
Public Member Functions | |
| void *TIDY_CALL * | alloc (TidyAllocator *self, size_t nBytes) |
| Called to allocate a block of nBytes of memory. More... | |
| void *TIDY_CALL * | realloc (TidyAllocator *self, void *block, size_t nBytes) |
| Called to resize (grow, in general) a block of memory. More... | |
| void (TIDY_CALL *free)(TidyAllocator *self | |
| Called to free a previously allocated block of memory. More... | |
| void (TIDY_CALL *panic)(TidyAllocator *self | |
| Called when a panic condition is detected. More... | |
Data Fields | |
| void * | block |
| ctmbstr | msg |
| void* TIDY_CALL* _TidyAllocatorVtbl::alloc | ( | TidyAllocator * | self, |
| size_t | nBytes | ||
| ) |
Called to allocate a block of nBytes of memory.
| void* TIDY_CALL* _TidyAllocatorVtbl::realloc | ( | TidyAllocator * | self, |
| void * | block, | ||
| size_t | nBytes | ||
| ) |
Called to resize (grow, in general) a block of memory.
Must support being called with NULL.
| _TidyAllocatorVtbl::void | ( | TIDY_CALL * | free | ) |
Called to free a previously allocated block of memory.
| _TidyAllocatorVtbl::void | ( | TIDY_CALL * | panic | ) |
Called when a panic condition is detected.
Must support block == NULL. This function is not called if either alloc or realloc fails; it is up to the allocator to do this. Currently this function can only be called if an error is detected in the tree integrity via the internal function CheckNodeIntegrity(). This is a situation that can only arise in the case of a programming error in tidylib. You can turn off node integrity checking by defining the constant NO_NODE_INTEGRITY_CHECK during the build.
| typedef struct _TidyAllocator TidyAllocator |
| typedef struct _TidyAllocatorVtbl TidyAllocatorVtbl |
| typedef void(TIDY_CALL * TidyFree) (void *buf) |
| typedef void*(TIDY_CALL * TidyMalloc) (size_t len) |
| typedef void*(TIDY_CALL * TidyRealloc) (void *buf, size_t len) |
| Bool TIDY_CALL tidySetMallocCall | ( | TidyMalloc | fmalloc | ) |
Give Tidy a malloc() replacement.
| Bool TIDY_CALL tidySetReallocCall | ( | TidyRealloc | frealloc | ) |
Give Tidy a realloc() replacement.
1.8.9.1 
