mirror of https://github.com/pevans/erc-c.git
61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
/*
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* vm_di.c
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*
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* This code defines a very (very!) simplistic form of dependency
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* injection container. It's up to you to set the entries of the
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* container appropriately.
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*
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* This container is obviously _not type-safe_. It's just a bunch of
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* void pointers. This container, however, _is_ immutable; once you set
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* a value for a DI entry, it cannot be changed.
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*/
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#include <stdbool.h>
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#include <stdlib.h>
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#include "log.h"
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#include "vm_di.h"
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/*
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* I learned something new today: this array will be constructed with
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* zero-values for each entry because it is statically declared. See:
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* http://en.cppreference.com/w/c/language/initialization
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*/
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static void *di_table[VM_DI_SIZE];
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#ifdef TESTING
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static bool di_mutable = true;
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#else
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static bool di_mutable = false;
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#endif
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/*
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* Set the di table entry `ent` to `val`. If there is a _previous_
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* value assigned to ent, then this returns ERR_INVALID, and no
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* further assignment is allowed.
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*
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* NOTE: in testing, we _do_ allow multiple assignments to entries, so
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* as to make it easier to tear down and rebuild machines/cpus/etc.
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* between tests.
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*/
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int
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vm_di_set(int ent, void *val)
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{
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if (di_table[ent] != NULL && !di_mutable) {
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return ERR_INVALID;
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}
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di_table[ent] = val;
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return OK;
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}
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/*
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* Return the value assigned to the given ent, or NULL if no entry has
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* been defined before.
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*/
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void *
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vm_di_get(int ent)
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{
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return di_table[ent];
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}
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