Daniel Veillard | 88155d8 | 2004-03-25 10:43:16 +0000 | [diff] [blame] | 1 | /** |
| 2 | * section: Parsing |
| 3 | * synopsis: Parse an XML document chunk by chunk to a tree and free it |
| 4 | * purpose: Demonstrate the use of xmlCreatePushParserCtxt() and |
| 5 | * xmlParseChunk() to read an XML file progressively |
| 6 | * into a tree and and xmlFreeDoc() to free the resulting tree |
| 7 | * usage: parse4 test3.xml |
| 8 | * test: parse4 test3.xml |
| 9 | * author: Daniel Veillard |
| 10 | * copy: see Copyright for the status of this software. |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <libxml/parser.h> |
| 15 | #include <libxml/tree.h> |
| 16 | |
Daniel Veillard | 3cf6950 | 2004-06-16 22:52:59 +0000 | [diff] [blame] | 17 | #ifdef LIBXML_PUSH_ENABLED |
Daniel Veillard | 88155d8 | 2004-03-25 10:43:16 +0000 | [diff] [blame] | 18 | static FILE *desc; |
| 19 | |
| 20 | /** |
| 21 | * readPacket: |
| 22 | * @mem: array to store the packet |
| 23 | * @size: the packet size |
| 24 | * |
| 25 | * read at most @size bytes from the document and store it in @mem |
| 26 | * |
| 27 | * Returns the number of bytes read |
| 28 | */ |
| 29 | static int |
| 30 | readPacket(char *mem, int size) { |
| 31 | int res; |
| 32 | |
| 33 | res = fread(mem, 1, size, desc); |
| 34 | return(res); |
| 35 | } |
| 36 | |
| 37 | /** |
| 38 | * example4Func: |
| 39 | * @filename: a filename or an URL |
| 40 | * |
| 41 | * Parse the resource and free the resulting tree |
| 42 | */ |
| 43 | static void |
| 44 | example4Func(const char *filename) { |
| 45 | xmlParserCtxtPtr ctxt; |
| 46 | char chars[4]; |
Daniel Veillard | 88155d8 | 2004-03-25 10:43:16 +0000 | [diff] [blame] | 47 | xmlDocPtr doc; /* the resulting document tree */ |
| 48 | int res; |
| 49 | |
| 50 | /* |
| 51 | * Read a few first byte to check the input used for the |
| 52 | * encoding detection at the parser level. |
| 53 | */ |
| 54 | res = readPacket(chars, 4); |
| 55 | if (res <= 0) { |
| 56 | fprintf(stderr, "Failed to parse %s\n", filename); |
| 57 | return; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * Create a progressive parsing context, the 2 first arguments |
| 62 | * are not used since we want to build a tree and not use a SAX |
| 63 | * parsing interface. We also pass the first bytes of the document |
| 64 | * to allow encoding detection when creating the parser but this |
| 65 | * is optional. |
| 66 | */ |
| 67 | ctxt = xmlCreatePushParserCtxt(NULL, NULL, |
| 68 | chars, res, filename); |
| 69 | if (ctxt == NULL) { |
| 70 | fprintf(stderr, "Failed to create parser context !\n"); |
| 71 | return; |
| 72 | } |
| 73 | |
| 74 | /* |
| 75 | * loop on the input getting the document data, of course 4 bytes |
| 76 | * at a time is not realistic but allows to verify testing on small |
| 77 | * documents. |
| 78 | */ |
| 79 | while ((res = readPacket(chars, 4)) > 0) { |
| 80 | xmlParseChunk(ctxt, chars, res, 0); |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * there is no more input, indicate the parsing is finished. |
| 85 | */ |
| 86 | xmlParseChunk(ctxt, chars, 0, 1); |
| 87 | |
| 88 | /* |
| 89 | * collect the document back and if it was wellformed |
| 90 | * and destroy the parser context. |
| 91 | */ |
| 92 | doc = ctxt->myDoc; |
| 93 | res = ctxt->wellFormed; |
| 94 | xmlFreeParserCtxt(ctxt); |
| 95 | |
| 96 | if (!res) { |
| 97 | fprintf(stderr, "Failed to parse %s\n", filename); |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * since we don't use the document, destroy it now. |
| 102 | */ |
| 103 | xmlFreeDoc(doc); |
| 104 | } |
| 105 | |
| 106 | int main(int argc, char **argv) { |
| 107 | if (argc != 2) |
| 108 | return(1); |
| 109 | |
| 110 | /* |
| 111 | * this initialize the library and check potential ABI mismatches |
| 112 | * between the version it was compiled for and the actual shared |
| 113 | * library used. |
| 114 | */ |
| 115 | LIBXML_TEST_VERSION |
| 116 | |
| 117 | /* |
| 118 | * simulate a progressive parsing using the input file. |
| 119 | */ |
| 120 | desc = fopen(argv[1], "rb"); |
| 121 | if (desc != NULL) { |
| 122 | example4Func(argv[1]); |
| 123 | fclose(desc); |
| 124 | } else { |
| 125 | fprintf(stderr, "Failed to parse %s\n", argv[1]); |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Cleanup function for the XML library. |
| 130 | */ |
| 131 | xmlCleanupParser(); |
| 132 | /* |
| 133 | * this is to debug memory for regression tests |
| 134 | */ |
| 135 | xmlMemoryDump(); |
| 136 | return(0); |
| 137 | } |
Daniel Veillard | 3cf6950 | 2004-06-16 22:52:59 +0000 | [diff] [blame] | 138 | #else /* ! LIBXML_PUSH_ENABLED */ |
| 139 | int main(int argc, char **argv) { |
| 140 | fprintf(stderr, "Library not compiled with push parser support\n"); |
| 141 | return(1); |
| 142 | } |
| 143 | #endif |