48 lines
1.7 KiB
Plaintext
48 lines
1.7 KiB
Plaintext
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How do I use APR'ized programs in connection with programs that don't
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use APR? These darn incomplete types don't let me fill out the APR types.
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The APR developers acknowledge that most programs are not using APR, and
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we don't expect them to migrate to using APR just because APR has been
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released. So, we have provided a way for non-APR'ized programs to interact
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very cleanly with APR.
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There are a set of functions, all documented in apr_portable.h, which allow
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a programmer to either get a native type from an APR type, or to setup an
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APR type from a native type.
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For example, if you are writing an add-on to another program that does not use
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APR for file I/O, but you (in your infinite wisdom) want to use APR to make
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sure your section is portable. Assume the program provides a type foo_t with
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a file descriptor in it (fd).
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void function_using_apr(foo_t non_apr_struct, ap_pool_t *p)
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{
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ap_file_t *apr_file = NULL;
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ap_put_os_file(&apr_file, &non_apr_struct->fd, p);
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...
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}
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There are portable functions for each APR incomplete type. They are all
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called ap_put_os_foobar(), and they each take the same basic arguments, a
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pointer to a pointer to the incomplete type (the last pointer in that list
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should be NULL), a pointer to the native type, and a pool. Each of these can
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be found in apr_portable.h.
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If you have to do the exact opposite (take an APR type and convert it to a
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native type, there are functions for that too. For example:
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void function_not_using_apr(apr_file_t *apr_file)
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{
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int unix_file_desc;
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ap_get_os_file(&unix_file_desc, apr_file);
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...
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}
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For each ap_put_os_foobar, there is a corresponding ap_get_os_file. These are
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also documented in apr_portable.h.
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