| 1 | #include "Python.h"
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| 2 | #include "pyarena.h"
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| 3 |
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| 4 | /* A simple arena block structure.
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| 5 |
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| 6 | Measurements with standard library modules suggest the average
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| 7 | allocation is about 20 bytes and that most compiles use a single
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| 8 | block.
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| 9 |
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| 10 | TODO(jhylton): Think about a realloc API, maybe just for the last
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| 11 | allocation?
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| 12 | */
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| 13 |
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| 14 | #define DEFAULT_BLOCK_SIZE 8192
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| 15 | #define ALIGNMENT 8
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| 16 | #define ALIGNMENT_MASK (ALIGNMENT - 1)
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| 17 | #define ROUNDUP(x) (((x) + ALIGNMENT_MASK) & ~ALIGNMENT_MASK)
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| 18 |
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| 19 | typedef struct _block {
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| 20 | /* Total number of bytes owned by this block available to pass out.
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| 21 | * Read-only after initialization. The first such byte starts at
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| 22 | * ab_mem.
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| 23 | */
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| 24 | size_t ab_size;
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| 25 |
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| 26 | /* Total number of bytes already passed out. The next byte available
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| 27 | * to pass out starts at ab_mem + ab_offset.
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| 28 | */
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| 29 | size_t ab_offset;
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| 30 |
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| 31 | /* An arena maintains a singly-linked, NULL-terminated list of
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| 32 | * all blocks owned by the arena. These are linked via the
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| 33 | * ab_next member.
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| 34 | */
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| 35 | struct _block *ab_next;
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