/* pageroute.c
 *
 * manages routing of pages where a consistent dynamo target is required.
 *
 * jim frost 11.10.97
 *
 * Copyright (C) 1997 Art Technology Group, Inc.
 * All Rights Reserved.  No use, copying or distribution of this
 * work may be made except in accordance with a valid license
 * agreement from Art Technology Group.  This notice must be
 * included on all copies, modifications and derivatives of this
 * work.
 */

#include <string.h>
#include <memory.h>
#include <stdlib.h>
#include "pageroute.h"

#ifdef SOLARIS2
char *strdup(const char *);     /* morons forgot to include it in string.h */
#endif                          /* SOLARIS2 */

/* An entry in the statically routed page table.
 */
typedef struct RoutedPage {
    /* the URL or prefix portion of the URL of a routed page.
     */
    char *url;

    /* the length of the URL string to compare if this is a prefix URL.
     */
    int prefixLen;

    /* next page in table
     */
    struct RoutedPage *next;
} RoutedPage;

/* The statically routed page table.
 */
static RoutedPage *PageTable;

#if 1                           /* debug code */
#include <stdio.h>
void debugOut(const char *message)
{
    FILE *fp;

    fp = fopen("d:\\debug.log", "a");
    if (fp == NULL)
        return;
    fwrite(message, 1, strlen(message), fp);
    fclose(fp);
}

void debugOutInt(int value)
{
    char buf[32];
    sprintf(buf, "%d", value);
    debugOut(buf);
}
#endif                          /* debug code */

/*----------------------------------------------------------------------------
 * Appends a page or list of pages to the page list.
 */
static void appendPage(RoutedPage * newPage)
{
    if (PageTable == NULL)
        PageTable = newPage;
    else {
        RoutedPage *rp;

        for (rp = PageTable; rp->next != NULL; rp = rp->next)
            /* EMPTY */ ;
        rp->next = newPage;
    }
}

/*----------------------------------------------------------------------------
 * Looks for a trailing asterisk and sets the prefix length if it finds one.
 */
static void setPrefixValue(RoutedPage * rp)
{
    int len = strlen(rp->url);
    if ((len > 0) && (rp->url[len - 1] == '*'))
        rp->prefixLen = len - 1;
}

/*----------------------------------------------------------------------------
 * Adds another statically routed page to the table.
 */
int addStaticallyRoutedPage(const char *pageUrl)
{
    RoutedPage *rp = (RoutedPage *) calloc(1, sizeof(RoutedPage));
    if (rp == NULL)
        return 0;
    rp->url = strdup(pageUrl);
    if (rp->url == NULL) {
        free(rp);
        return 0;
    }
    setPrefixValue(rp);
    appendPage(rp);
    return 1;
}

/*----------------------------------------------------------------------------
 * Adds a list of URLs (comma-delimited) to the statically routed page table.
 */
int addStaticallyRoutedPageList(const char *pageList)
{
    RoutedPage *newPages = NULL;
    RoutedPage *lastPage = NULL;
    const char *start = pageList;
    const char *end;

    while ((start != NULL) && (*start != '\0')) {
        char *url;
        RoutedPage *rp;

        /* skip leading comma delimiters
         */
        while (*start == ',')
            start++;

        /* look for trailing comma delimiter
         */
        end = strchr(start, ',');
        if (end == NULL) {
            url = strdup(start);
            if (url == NULL)
                goto cleanupAndFail;
        } else {
            int len = end - start;
            url = (char *) malloc(len + 1);
            if (url == NULL)
                goto cleanupAndFail;
            strncpy(url, start, len);
            url[len] = '\0';
        }

        rp = (RoutedPage *) calloc(1, sizeof(RoutedPage));
        if (rp == NULL) {
            free(url);
            goto cleanupAndFail;
        }
        rp->url = url;
        setPrefixValue(rp);

        /* append to the new page list
         */
        if (lastPage == NULL)
            newPages = lastPage = rp;
        else {
            lastPage->next = rp;
            lastPage = rp;
        }
        start = end;
    }

    /* concatenate the new page and routed page lists.
     */
    if (newPages != NULL)
        appendPage(newPages);

    return 1;

  cleanupAndFail:
    /* clean up anything in the new page list
     */
    while (newPages != NULL) {
        RoutedPage *oldrp = newPages;
        newPages = newPages->next;
        if (oldrp->url != NULL)
            free(oldrp->url);
        free(oldrp);
    }
    return 0;
}

/*----------------------------------------------------------------------------
 * Clears the statically routed page table.
 */
void clearStaticallyPageTable(void)
{
    while (PageTable != NULL) {
        RoutedPage *oldrp = PageTable;
        PageTable = PageTable->next;
        if (oldrp->url != NULL)
            free(oldrp->url);
        free(oldrp);
    }
}

/*----------------------------------------------------------------------------
 * Computes a hash value for a string using a 32-bit CRC.
 */
int getStringHashValue(const char *string)
{
    unsigned int crc32_table[256] = {   /* lookup table */
        0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419,
            0x706AF48F,
        0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E,
            0x97D2D988,
        0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064,
            0x6AB020F2,
        0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551,
            0x83D385C7,
        0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F,
            0x63066CD9,
        0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4,
            0xA2677172,
        0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA,
            0x42B2986C,
        0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF,
            0xABD13D59,
        0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5,
            0x56B3C423,
        0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2,
            0xB10BE924,
        0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190,
            0x01DB7106,
        0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5,
            0xE8B8D433,
        0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB,
            0x086D3D2D,
        0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8,
            0xF262004E,
        0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6,
            0x12B7E950,
        0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3,
            0xFBD44C65,
        0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541,
            0x3DD895D7,
        0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846,
            0xDA60B8D0,
        0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C,
            0x270241AA,
        0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409,
            0xCE61E49F,
        0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17,
            0x2EB40D81,
        0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C,
            0x74B1D29A,
        0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12,
            0x94643B84,
        0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27,
            0x7D079EB1,
        0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D,
            0x806567CB,
        0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A,
            0x67DD4ACC,
        0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8,
            0xA1D1937E,
        0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD,
            0x48B2364B,
        0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3,
            0xA867DF55,
        0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0,
            0x5268E236,
        0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE,
            0xB2BD0B28,
        0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B,
            0x5BDEAE1D,
        0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9,
            0xEB0E363F,
        0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE,
            0x0CB61B38,
        0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4,
            0xF1D4E242,
        0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1,
            0x18B74777,
        0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF,
            0xF862AE69,
        0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354,
            0x3903B3C2,
        0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A,
            0xD9D65ADC,
        0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F,
            0x30B5FFE9,
        0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605,
            0xCDD70693,
        0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02,
            0x2A6F2B94,
        0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
    };

    unsigned int crc;           /* CRC value */
    int i;

    crc = 0xFFFFFFFF;           /* preconditioning sets non zero value */
    /* loop through the file and calculate CRC */
    for (i = 0; string[i] != '\0'; i++) {
        int v = (crc ^ string[i]) & 0x000000FF;
        crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32_table[v];
    }

    return ~crc;                /* postconditioning */
}

/*----------------------------------------------------------------------------
 * Returns true if the URL is found in the statically routed page table.
 */
int isStaticallyRoutedPage(const char *url)
{
    RoutedPage *rp;

    for (rp = PageTable; rp != NULL; rp = rp->next) {
        if (rp->prefixLen > 0) {        /* compare URL prefix rather than a whole URL */
            if (!strncmp(rp->url, url, rp->prefixLen))
                return 1;
        } else {
            if (!strcmp(rp->url, url))
                return 1;
        }
    }
    return 0;
}
