36 lines
1019 B
36 lines
1019 B
allocation growing API |
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====================== |
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Dynamically growing an array using realloc() is error prone and boring. |
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Define your array with: |
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* a pointer (`item`) that points at the array, initialized to `NULL` |
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(although please name the variable based on its contents, not on its |
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type); |
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* an integer variable (`alloc`) that keeps track of how big the current |
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allocation is, initialized to `0`; |
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* another integer variable (`nr`) to keep track of how many elements the |
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array currently has, initialized to `0`. |
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Then before adding `n`th element to the item, call `ALLOC_GROW(item, n, |
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alloc)`. This ensures that the array can hold at least `n` elements by |
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calling `realloc(3)` and adjusting `alloc` variable. |
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------------ |
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sometype *item; |
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size_t nr; |
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size_t alloc |
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for (i = 0; i < nr; i++) |
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if (we like item[i] already) |
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return; |
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/* we did not like any existing one, so add one */ |
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ALLOC_GROW(item, nr + 1, alloc); |
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item[nr++] = value you like; |
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------------ |
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You are responsible for updating the `nr` variable.
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