TB9.2 Example Applications: examples/PIPS/openclibz/src/compress.c Source File

00001 /*
+00002 * ==============================================================================
+00003 *  Name        : Compress.c
+00004 *  Part of     : OpenCLibz
+00005 *  Interface   : 
+00006 *  Description : 
+00007 *  Version     : 
+00008 *
+00009 *  Copyright (c) 2007 Nokia Corporation.
+00010 *  This material, including documentation and any related 
+00011 *  computer programs, is protected by copyright controlled by 
+00012 *  Nokia Corporation.
+00013 * ==============================================================================
+00014 */
+00015 
+00016 
+00017 
+00026 #include "OpenCLibzheader.h"
+00027 #include <limits.h>
+00028 
+00029 //
+00030 // GzCompress
+00031 // Compress the input file "in" and generates "out" file
+00032 //
+00033 void GzCompress(FILE   *in,gzFile out)
+00034 {
+00035     static char buf[BUFLEN];
+00036     int len;
+00037     
+00038 
+00039 #ifdef USE_MMAP
+00040     /* Try first compressing with mmap. If mmap fails 
+00041      use the normal fread loop.
+00042      */
+00043     if (GzCompressMmap(in, out) == Z_OK) return;
+00044 #endif
+00045     for (;;) 
+00046     {
+00047         len = (int)fread(buf, 1, sizeof(buf), in);
+00048         if (len < 0) 
+00049         Error("error reading the file \n");
+00050     
+00051         if (len == 0) break;
+00052 
+00053         if (gzwrite(out, buf, (unsigned)len) != len) 
+00054         Error("error writing to the file \n");;
+00055         
+00056     }
+00057     fclose(in);
+00058     
+00059     if (gzclose(out) != Z_OK) // libz api to close a compressed file 
+00060     Error("failed gzclose");
+00061 }
+00062 
+00063 
+00064 
+00065 
+00066 
+00067 
+00068 #ifdef USE_MMAP 
+00069 
+00070 //
+00071 // GzCompressMmap
+00072 // Try compressing the input file at once using mmap. Return Z_OK 
+00073 // If success, otherwise it returns Z_ERRNO .
+00074 // 
+00075 int GzCompressMmap(FILE   * in,gzFile out)
+00076 {
+00077     int len;
+00078     int err;
+00079     int ifd = fileno(in);
+00080     caddr_t buf;    /* mmap'ed buffer for the entire input file */
+00081     off_t buf_len;  /* length of the input file */
+00082     struct stat sb;
+00083 
+00084     /* Determine the size of the file, needed for mmap: */
+00085     
+00086     if (fstat(ifd, &sb) < 0) 
+00087     return Z_ERRNO;
+00088     
+00089     buf_len = sb.st_size;
+00090     
+00091     if (buf_len <= 0) 
+00092     return Z_ERRNO;
+00093 
+00094     /* Now do the actual mmap: */
+00095     
+00096     buf =(char*) mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
+00097     
+00098     //mmap is an openc api 
+00099     
+00100     if (buf == (caddr_t)(-1)) 
+00101     return Z_ERRNO;
+00102 
+00103     /* Compress the whole file at once: */
+00104     len = gzwrite(out, (char *)buf, (unsigned)buf_len);
+00105 
+00106     if (len != (int)buf_len) 
+00107     Error(gzerror(out, &err));
+00108 
+00109     munmap(buf, buf_len);
+00110     fclose(in);
+00111     if (gzclose(out) != Z_OK) // libz api to close a compressed file 
+00112     Error("failed gzclose");
+00113     
+00114     return Z_OK;
+00115 }
+00116 #endif /* USE_MMAP */
+00117 
+00118 
+00119 
+00120 
+00121 
+00122 //
+00123 // -----------------------------------------------------------------------------
+00124 // FileCompress
+00125 // Compresses the file using mode value
+00126 // -----------------------------------------------------------------------------
+00127 //
+00128 void FileCompress(char  * file,char  * mode)
+00129 {
+00130     static char outfile[MAX_NAME_LEN];
+00131     FILE  *in;
+00132     gzFile out;
+00133         char choice[3];
+00134 
+00135     strcpy(outfile, file);
+00136     strcat(outfile, GZ_SUFFIX);
+00137 
+00138     in = fopen(file, "rb");
+00139     if (in == NULL) 
+00140     {    
+00141     Error("file not found ...try again \n");
+00142     }
+00143     out = gzopen(outfile, mode);
+00144     if (out == NULL) 
+00145     {       
+00146     Error("error opening outfile\n ");        
+00147     }
+00148     GzCompress(in, out);
+00149    
+00150     
+00151     printf("do you want to delete the original file (y /n) \n");
+00152     
+00153     scanf("%s",choice);
+00154     /*I am using scanf("%s",...) because of some problem in getchar() as 
+00155     well as scanf("%c"...) .   I have reported the bug */
+00156     
+00157     if(choice[0] == 'y')
+00158     unlink(file);
+00159     
+00160     printf(" Congrats .... compression done ...u can find .gz file in the same directory as of the source file\n");
+00161 }
+00162 
+00163 //
+00164 // -----------------------------------------------------------------------------
+00165 // StringCompress
+00166 // Compresses the string
+00167 // This function compresses the string entered by the user and shows the
+00168 // compressed string and then decompressess it 
+00169 // Actually This function will show the content on the screen and demonstarte 
+00170 // how strings can be compressed
+00171 // -----------------------------------------------------------------------------
+00172 //
+00173 
+00174 void StringCompress()
+00175 {
+00176     Byte *compr, *uncompr;
+00177     uLong len,comprLen,uncomprLen;
+00178     char *hello;
+00179      
+00180     hello = (char *)malloc(100*sizeof(char));
+00181   
+00182     printf("enter the string(maximum 100 characters) to compress....\n");
+00183 
+00184 
+00185 
+00186     scanf("%s",hello); //accepts the string from the user
+00187     len = (uLong)strlen(hello)+1;
+00188     comprLen = 10 * len; 
+00189     uncomprLen = comprLen;
+00190     
+00191     //memory allocation
+00192     compr    = (Byte*)calloc((uInt)comprLen, 1);  
+00193     uncompr  = (Byte*)calloc((uInt)uncomprLen, 1);
+00194                 
+00195                 
+00196                 
+00197     //compress is one of the api of libz library used to compress data
+00198     
+00199     compress(compr, &comprLen, (const Bytef*)hello, len);
+00200 
+00201     strcpy((char*)uncompr, "garbage"); //initialization
+00202     
+00203     printf("compressed string is : %s\n\n", (char *)compr);
+00204 
+00205     //uncompress is one of the api of libz library used to uncompress data
+00206     
+00207     uncompress(uncompr, &uncomprLen, compr, comprLen);
+00208 
+00209    
+00210     printf("press enter to uncompress it\n");
+00211     
+00212     getchar();
+00213     getchar();
+00214     
+00215     if (strcmp((char*)uncompr, hello)) 
+00216     {
+00217         Error("bad uncompress\n");  
+00218         free(compr);
+00219         free(uncompr);        
+00220     }
+00221     else 
+00222     {
+00223         printf("uncompressed string is : %s\n", (char *)uncompr);
+00224         free(compr);
+00225         free(uncompr);
+00226     }
+00227     
+00228 }
+00229 
+00230 /*  End of File */
+