| 1 |
Major parsing routines are built according to this template: |
| 2 |
|
| 3 |
int psiconv_parse_TYPE (const psiconv_buffer buf, int lev, |
| 4 |
psiconv_u32 off, int *length, |
| 5 |
psiconv_TYPE *result) |
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{ |
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int res = 0; |
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int len = 0; |
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int leng; |
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|
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psiconv_progress(lev+1,off,"Going to parse TYPE"); |
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if (!(*result = malloc(sizeof(**result)))) |
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goto ERROR1; |
| 14 |
|
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/* Example of calling some other parse function */ |
| 16 |
if ((res = psiconv_parse_TYPE2(buf,lev+2,off+len,&leng, |
| 17 |
&(*result)->FIELD2))) |
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goto ERROR2; |
| 19 |
psiconv_debug(lev+2,off+len,"Some helpful message"); |
| 20 |
len += leng; |
| 21 |
|
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/* Example of reading some bytes directly */ |
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(*result)->FIELD1 = psiconv_read_u8(buf,lev+2,off+len,&res); |
| 24 |
if (!res) |
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goto ERROR3; |
| 26 |
psiconv_debug(lev+2,off+len,"Some helpful message"); |
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len ++; |
| 28 |
|
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psiconv_debug(lev+2,off+len,"Some helpful message"); |
| 30 |
if (length) |
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*length = len; |
| 32 |
psiconv_progress(lev+1,off+len-1,"End of TYPE (total length: %08x)", |
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len); |
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return 0; |
| 35 |
|
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ERROR3: |
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free ((*result)->FIELD2) |
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ERROR2: |
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free (*result); |
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ERROR1: |
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psiconv_warn(lev+1,off,"Reading of TYPE failed"); |
| 42 |
if (length) |
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*length = 0; |
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if (!res) |
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return -PSICONV_E_NOMEM; |
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else |
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return res; |
| 48 |
} |
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|
| 50 |
If something unexpected happens half-way, but you can recover from it |
| 51 |
(for example, an unexpected value in some well-defined field), call |
| 52 |
psiconv_warn, but do not return with an error. The rule is that if |
| 53 |
the result code of a procedure is not 0, you may assume that things |
| 54 |
are hopeless, that nothing was allocated, and that every field contains |
| 55 |
nonsense. |
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