| 1 | #include "EXTERN.h" |
1 | #include "EXTERN.h" |
| 2 | #include "perl.h" |
2 | #include "perl.h" |
| 3 | #include "XSUB.h" |
3 | #include "XSUB.h" |
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4 | |
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5 | #include <string.h> |
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6 | |
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7 | // a compiler supporting C99 is required |
| 4 | |
8 | |
| 5 | /* try to be compatible with older perls */ |
9 | /* try to be compatible with older perls */ |
| 6 | /* SvPV_nolen() macro first defined in 5.005_55 */ |
10 | /* SvPV_nolen() macro first defined in 5.005_55 */ |
| 7 | /* this is slow, not threadsafe, but works */ |
11 | /* this is slow, not threadsafe, but works */ |
| 8 | #include "patchlevel.h" |
12 | #include "patchlevel.h" |
| … | |
… | |
| 12 | #endif |
16 | #endif |
| 13 | #if PATCHLEVEL < 6 |
17 | #if PATCHLEVEL < 6 |
| 14 | # define call_sv perl_call_sv |
18 | # define call_sv perl_call_sv |
| 15 | #endif |
19 | #endif |
| 16 | |
20 | |
| 17 | MODULE = DBIx::Tree PACKAGE = DBIx::Tree |
21 | #define KEYLEN 8 // number of bytes in the l, m, r fields |
| 18 | |
22 | |
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23 | static SV * |
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24 | new_key (void) |
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25 | { |
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26 | SV *new = NEWSV(0, KEYLEN); |
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27 | SvPOK_only (new); |
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28 | SvCUR_set (new, KEYLEN); |
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29 | |
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30 | return new; |
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31 | } |
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32 | |
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33 | MODULE = XML::DB PACKAGE = XML::DB::Key |
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34 | |
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35 | PROTOTYPES: ENABLE |
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36 | |
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37 | int |
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38 | KEYLEN() |
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39 | CODE: |
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40 | RETVAL = KEYLEN; |
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41 | OUTPUT: |
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42 | RETVAL |
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43 | |
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44 | SV * |
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45 | 0() |
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46 | ALIAS: |
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47 | 1 = 255 |
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48 | CODE: |
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49 | RETVAL = new_key (); |
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50 | memset (SvPVX (RETVAL), ix, KEYLEN); |
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51 | OUTPUT: |
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52 | RETVAL |
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53 | |
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54 | # calculcate l + r |
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55 | SV * |
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56 | m(ls,rs) |
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57 | SV * ls |
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58 | SV * rs |
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59 | CODE: |
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60 | unsigned char *l, *m, *r, *me; |
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61 | unsigned int mx, carry; |
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62 | |
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63 | RETVAL = new_key (); |
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64 | |
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65 | l = SvPVX (ls ) + KEYLEN; |
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66 | r = SvPVX (rs ) + KEYLEN; |
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67 | m = (me = SvPVX (RETVAL)) + KEYLEN; |
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68 | |
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69 | me [0] = 'U'; |
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70 | me [1] = 'U'; |
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71 | |
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72 | mx = (unsigned int)*--l + (unsigned int)*--r + 1; *--m = (mx & 0x0ff) >> 1; |
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73 | carry = mx & 0x100; |
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74 | |
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75 | do |
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76 | { |
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77 | mx = (unsigned int)*--l + (unsigned int)*--r + (carry >> 8); *--m = (mx & 0x0ff) >> 1; |
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78 | |
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79 | m[1] |= (mx & 0x001) << 7; |
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80 | carry = (mx & 0x100); |
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81 | } |
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82 | while (me < m); |
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83 | |
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84 | m[0] |= carry >> 1; |
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85 | |
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86 | OUTPUT: |
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87 | RETVAL |
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88 | |
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89 | |
