path: root/mbbsd/pmore.c

#include "bbs.h"

/*
 * piaip's new implementation of pager(more) with mmap,
 * designed for unlimilited length(lines).
 *
 * Author: Hung-Te Lin (piaip), 2005
 * <piaip@csie.ntu.edu.tw>
 */

#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <string.h>

// Platform Related
#ifndef MAP_NOSYNC
#define MAP_NOSYNC MAP_SHARED
#endif

//#define DEBUG

typedef struct
{
    unsigned char 
    *start , *end,  // file buffer
    *disps, *dispe, // disply start/end
    *maxdisps;  // a very special pointer, 
                //   consider as "disps of last page"
    off_t len,      // file total length
      lineno;   // lineno of disps

} MmappedFile;

MmappedFile mf = { 0, 0, 0, 0, 0 }; // current file

/* mf_* navigation commands and return value meanings */
enum {
    MFNAV_OK,       // navigation ok
    MFNAV_EXCEED,   // request exceeds buffer
} MF_NAV_COMMANDS;

#define MFNAV_PAGE (t_lines-2)
#define RESETMF() memset(&mf, 0, sizeof(mf));
#define ANSI_ESC (0x1b)

int mf_backward(int);

/* search records */
enum {
    MFSEARCH_FORWARD,
    MFSEARCH_BACKWARD,
} MFSEARCH_DIRECTION;

typedef struct
{
    int  len;
    int (*cmpfunc) (const char *, const char *, size_t);
    char search_str[81];
} SearchRecord;

SearchRecord sr = { 0, strncmp, "" };

/* 
 * mmap basic operations 
 */
int mf_attach(unsigned char *fn)
{
    struct stat st;
    int fd = open(fn, O_RDONLY, 0600);

    if(fd < 0)
    return 0;

    if (fstat(fd, &st) || ((mf.len = st.st_size) <= 0) || S_ISDIR(st.st_mode))
    {
    mf.len = 0;
    close(fd);
    return 0;
    }

//    mf.len = lseek(fd, 0L, SEEK_END);
//    lseek(fd, 0, SEEK_SET);

    mf.start = mmap(NULL, mf.len, PROT_READ, 
        MAP_NOSYNC, fd, 0);
    close(fd);

    if(mf.start == MAP_FAILED)
    {
    RESETMF();
    return 0;
    }

    mf.end = mf.start + mf.len;
    mf.disps = mf.dispe = mf.start;
    mf.lineno = 0;
    // build maxdisps
    mf.disps = mf.end - 1;
    mf_backward(MFNAV_PAGE);
    mf.maxdisps = mf.disps;
    mf.disps = mf.dispe = mf.start;
    mf.lineno = 0;
    return  1;
}

void mf_detach()
{
    if(mf.start) {
    munmap(mf.start, mf.len);
    RESETMF();
    }
}

/*
 * lineno calculation, and moving
 */
void mf_sync_lineno()
{
    unsigned char *p;
    mf.lineno = 0;
    for (p = mf.start; p < mf.disps; p++)
    if(*p == '\n')
        mf.lineno ++;
}

int mf_backward(int lines)
{
    int flFirstLine = 1;
    // first, because we have to trace back to line beginning,
    // add one line.
    lines ++;

    // now try to rollback for lines
    if(lines == 1)
    {
    /* special case! just rollback to start */
    while ( mf.disps > mf.start && 
        *(mf.disps-1) != '\n')
        mf.disps --;
    mf.disps --;
    lines --;
    }
    else while(mf.disps > mf.start && lines > 0)
    {
    while (mf.disps > mf.start && *--mf.disps != '\n');
    if(flFirstLine)
    {
        flFirstLine = 0; lines--;
        continue;
    }

    if(mf.disps >= mf.start) 
        mf.lineno--, lines--;
    }

    if(mf.disps == mf.start)
    mf.lineno = 0;
    else
    mf.disps ++;

    if(lines > 0)
    return MFNAV_OK;
    else
    return MFNAV_EXCEED;
}

int mf_forward(int lines)
{
    while(mf.disps <= mf.maxdisps && lines > 0)
    {
    while (mf.disps <= mf.maxdisps && *mf.disps++ != '\n');

    if(mf.disps <= mf.maxdisps)
        mf.lineno++, lines--;
    }

    if(mf.disps > mf.maxdisps)
    mf.disps = mf.maxdisps;

    if(lines > 0)
    return MFNAV_OK;
    else
    return MFNAV_EXCEED;
}

int mf_goTop()
{
    mf.disps = mf.start;
    mf.lineno = 0;
    return MFNAV_OK;
}

int mf_goBottom()
{
    mf.disps = mf.end-1;
    mf_backward(MFNAV_PAGE);
    // lineno?
    mf_sync_lineno();
    return MFNAV_OK;
}

int mf_goto(int lineno)
{
    mf.disps = mf.start;
    mf.lineno = 0;
    return mf_forward(lineno);
}

int mf_viewedNone()
{
    return (mf.disps <= mf.start);
}

int mf_viewedAll()
{
    return (mf.dispe >= mf.end-1);
}
/*
 * search!
 */
int mf_search(int direction)
{
    unsigned char *s = sr.search_str;
    int l = sr.len;
    int flFound = 0;

    if(!*s)
    return 0;

    if(direction ==  MFSEARCH_FORWARD) 
    {
    mf_forward(1);
    while(mf.disps < mf.end - l)
    {
        if(sr.cmpfunc(mf.disps, s, l) == 0)
        {
        flFound = 1;
        break;
        } else
        mf.disps ++;
    }
    mf_backward(0);
    if(mf.disps > mf.maxdisps)
        mf.disps = mf.maxdisps;
    mf_sync_lineno();
    } 
    else if(direction ==  MFSEARCH_BACKWARD) 
    {
    mf_backward(1);
    while (!flFound && mf.disps > mf.start)
    {
        while(!flFound && mf.disps < mf.end-l && *mf.disps != '\n')
        {
        if(sr.cmpfunc(mf.disps, s, l) == 0)
        {
            flFound = 1;
        } else
            mf.disps ++;
        }
        if(!flFound)
        mf_backward(1);
    }
    mf_backward(0);
    if(mf.disps < mf.start)
        mf.disps = mf.start;
    mf_sync_lineno();
    }
    return flFound;
}

/*
 * Format Related
 */
typedef struct
{
    int lines;  // header lines
    int authorlen;
    int boardlen;
} ArticleHeader;

ArticleHeader ah;

void mf_parseHeader()
{
    /* format:
     * AUTHOR: author BOARD: blah
     * XXX: xxx
     * XXX: xxx
     * [blank, fill with seperator]
     *
     * #define STR_AUTHOR1     "作者:"
     * #define STR_AUTHOR2     "發信人:"
     * #define STR_POST1       "看板:"
     * #define STR_POST2       "站內:"
     */
    ah.lines    = -1;
    ah.authorlen= -1;
    ah.boardlen = -1;
    if(mf.len > LEN_AUTHOR2)
    {
    if (strncmp(mf.start, STR_AUTHOR1, LEN_AUTHOR1) == 0)
    {
        ah.lines = 3;   // local
        ah.authorlen = LEN_AUTHOR1;
    } 
    else if (strncmp(mf.start, STR_AUTHOR2, LEN_AUTHOR2) == 0)
    {
        ah.lines = 4;
        ah.authorlen = LEN_AUTHOR2;
    }
    /* traverse for author length */
    {
        unsigned char *p = mf.start;
        unsigned char *pb = p;

        /* first, go to line-end */
        while(p < mf.end && *p != '\n')
        p++;
        pb = p;
        /* next, rollback for ':' */
        while(p > mf.start && *p != ':')
        p--;
        if(p > mf.start && *p == ':')
        {
        ah.boardlen = pb - p;
        while (p > mf.start && *p != ' ')
            p--;
        if( *p == ' ')
        {
            ah.authorlen = p - mf.start - ah.authorlen;
        } else
            ah.boardlen = -1, ah.authorlen = -1;
        } else
        ah.authorlen = -1;
    }
    }
}

/*
 * display mf content from disps for MFNAV_PAGE+1
 */
#define STR_ANSICODE    "[0123456789;,"
#define DISP_HEADS_LEN (4)  // strlen of each heads
static char  *disp_heads[] = {"作者", "標題", "時間", "轉信"};

void mf_disp()
{
    int lines = 0, col = 0, currline = 0;

    mf.dispe = mf.disps;
    while (lines < MFNAV_PAGE+1) 
    {
    int inAnsi = 0;

    currline = mf.lineno + lines;
    col = 0;

    if (currline < ah.lines)
    {
        int w = t_columns - 2, i_author = 0;
        int flDrawBoard = 0, flDrawAuthor = 0;
        char *ph = disp_heads[currline];

        /* case 1, we're printing headers */

        if (currline == 0 && ah.boardlen > 0)
        flDrawAuthor = 1;
draw_header:
        if(flDrawAuthor)
        w = t_columns - 2 - ah.boardlen - 6;
        else
        w = t_columns - 2;

        outs("\033[47;34m "); col++;

        /* special case for STR_AUTHOR2 */
        if(!flDrawBoard)
        {
        outs(ph);
        col += DISP_HEADS_LEN;  // strlen(disp_heads[currline])
        } else {
        /* display as-is */
        while (*mf.dispe != ':' && *mf.dispe != '\n')
        if(col++ < t_columns)
            outc(*mf.dispe++);
        }

        while (*mf.dispe != ':' && *mf.dispe != '\n')
        mf.dispe ++;

        if(*mf.dispe == ':') {
        outs(" \033[44;37m"); col++;
        mf.dispe ++;
        }

        while (col < w) {   // -2 to match seperator
        int flCanDraw = (*mf.dispe != '\n');

        if(flDrawAuthor)
            flCanDraw = i_author < ah.authorlen;
        if(flCanDraw)
        {
            /* strip ansi in headers */
            unsigned char c = *mf.dispe++;
            if(inAnsi)
            {
            if (!strchr(STR_ANSICODE, c))
                inAnsi = 0;
            } else {
            if(c == ANSI_ESC)
                inAnsi = 1;
            else
                outc(c), col++, i_author++;
            }
        } else {
            outc(' '), col++;
        }
        }

        if (flDrawAuthor)
        {
        flDrawBoard = 1;
        flDrawAuthor = 0;
        while(*mf.dispe == ' ')
            mf.dispe ++;
        goto draw_header;
        }

        outs("\033[m");
        // skip to end of line
        while(mf.dispe < mf.end && *mf.dispe != '\n')
        mf.dispe++;
    } 
    else if (currline == ah.lines)
    {
        /* case 2, header seperator line */
        outs("\033[36m");
        for(col = 0; col < t_columns -2; col+=2)
        {
        outs("─");
        }
        outs("\033[m");
        while(mf.dispe < mf.end && *mf.dispe != '\n')
        mf.dispe++;
    } 
    else if(mf.dispe < mf.end)
    {
        /* case 3, normal text */
        long dist = mf.end - mf.dispe;
        long flResetColor = 0;
        int  srlen = -1;

        // first check quote
        if(dist > 1 && 
            (*mf.dispe == ':' || *mf.dispe == '>') && 
            *(mf.dispe+1) == ' ')
        {
        outs("\033[36m");
        flResetColor = 1;
        } else if (dist > 2 && 
            (!strncmp(mf.dispe, "※", 2) || 
             !strncmp(mf.dispe, "==>", 3)))
        {
        outs("\033[32m");
        flResetColor = 1;
        }

        while(mf.dispe < mf.end && *mf.dispe != '\n')
        {
        if(inAnsi)
        {
            if (!strchr(STR_ANSICODE, *mf.dispe))
            inAnsi = 0;
            if(col < t_columns)
            outc(*mf.dispe);
        } else {
            if(*mf.dispe == ANSI_ESC)
            inAnsi = 1;
            else if(srlen < 0 && sr.search_str[0] && // support search
                //tolower(sr.search_str[0]) == tolower(*mf.dispe) &&
                mf.end - mf.dispe > sr.len &&
                sr.cmpfunc(mf.dispe, sr.search_str, sr.len) == 0)
            {
                outs("\033[7m"); 
                srlen = sr.len-1;
                flResetColor = 1;
            }

            if(col < t_columns)
            outc(*mf.dispe);
            if(!inAnsi)
            {
            col++;
            if (srlen == 0)
                outs("\033[m");
            if(srlen >= 0)
                srlen --;
            }
        }
        mf.dispe ++;
        }
        if(flResetColor)
        outs("\033[m");
    }

    if(mf.dispe < mf.end) 
        mf.dispe ++;
    if(col < t_columns)
        outc('\n');
    lines ++;
    }
}

/* --------------------- MAIN PROCEDURE ------------------------- */

static const char    * const pmore_help[] = {
    "\0閱\讀文章功\能鍵使用說明",
    "\01游標移動功\能鍵",
    "(↑)                  上捲一行",
    "(↓)(Enter)           下捲一行",
    "(^B)(PgUp)(BackSpace) 上捲一頁",
    "(→)(PgDn)(Space)     下捲一頁",
    "(0)(g)(Home)          檔案開頭",
    "($)(G) (End)          檔案結尾",
    "\01其他功\能鍵",
    "(/)                   搜尋字串",
    "(n/N)                 重複正/反向搜尋",
//    "(TAB)                 URL連結",
    "(Ctrl-T)              存到暫存檔",
    "(:/f/b)               跳至某頁/下/上篇",
    "(a/A)                 跳至同一作者下/上篇",
    "([-/]+)               主題式閱\讀 上/下",
    "(t)                   主題式循序閱\讀",
    "(q)(←)               結束",
    "(h)(H)(?)             輔助說明畫面",
    "\01本系統使用 piaip 的新式瀏覽程式",
    NULL
};

int pmore(char *fpath, int promptend)
{
    int  flExit = 0, retval = 0;
    int  ch = 0;

    STATINC(STAT_MORE);
    if(!mf_attach(fpath))
    return -1;

    /* reset and parse article header */
    memset(&ah, 0, sizeof(ah));
    mf_parseHeader();

    clear();
    while(!flExit)
    {
    clear();
    move(0, 0);
    mf_disp();

    if(promptend == NA && mf_viewedAll())
        break;

    move(b_lines, 0);

#ifdef DEBUG
    prints("L#%d prmpt=%d Disp:%08X/%08X/%08X, File:%08X/%08X(%d)",
        (int)mf.lineno, 
        promptend,
        (unsigned int)mf.disps, 
        (unsigned int)mf.maxdisps,
        (unsigned int)mf.dispe,
        (unsigned int)mf.start, (unsigned int)mf.end,
        mf.len);
#else
    if(mf.len)
    prints("\033[m\033[%sm  瀏覽 P.%d(%d%%)  %s  %-30.30s%s",
        "44", //printcolor[(int)color],
        (int)(mf.lineno / MFNAV_PAGE)+1,
        (int)((unsigned long)(mf.dispe-mf.start) * 100 / mf.len),
        "\033[31;47m",
        "(h)\033[30m求助  \033[31m→↓[PgUp][",
        "PgDn][Home][End]\033[30m游標移動  \033[31m←[q]\033[30m結束   \033[m");
#endif

    ch = igetch();
    switch (ch) {
        /* ------------------ EXITING KEYS ------------------ */
        case 'r': // Ptt: put all reply/recommend function here
        case 'R':
        case 'Y':
        case 'y':
        flExit = 1, retval = 999;
        break;
        case 'X':
        flExit = 1, retval = 998;
        break;
        case 'A':
        flExit = 1, retval = AUTHOR_PREV;
        break;
        case 'a':
        flExit = 1, retval = AUTHOR_NEXT;
        break;
        case 'F':
        case 'f':
        flExit = 1, retval = READ_NEXT;
        break;
        case 'B':
        case 'b':
        flExit = 1, retval = READ_PREV;
        break;
        case KEY_LEFT:
        case 'q':
        flExit = 1, retval = FULLUPDATE;
        break;

        /* from Kaede, thread reading */
        case ']':
        case '+':
        flExit = 1, retval = RELATE_NEXT;
        break;
        case '[':
        case '-':
        flExit = 1, retval = RELATE_PREV;
        break;
        case '=':
        flExit = 1, retval = RELATE_FIRST;
        break;
        case 't':
        if (mf_viewedAll())
            flExit = 1, retval = RELATE_NEXT;
        else
            mf_forward(MFNAV_PAGE);
        break;
        /* ------------------ NAVIGATION KEYS ------------------ */
        /* Simple Navigation */
        case Ctrl('F'):
        case KEY_PGDN:
        mf_forward(MFNAV_PAGE);
        break;
        case Ctrl('B'):
        case KEY_PGUP:
        mf_backward(MFNAV_PAGE);
        break;

        case '0':
        case 'g':
        case KEY_HOME:
        mf_goTop();
        break;
        case '$':
        case 'G':
        case KEY_END:
        mf_goBottom();
        break;

        /* Compound Navigation */
        case '\r':
        case '\n':
        case KEY_DOWN:
        if (mf_viewedAll() ||
            (promptend == 2 && (ch == '\r' || ch == '\n')))
            flExit = 1, retval = READ_NEXT;
        else
            mf_forward(1);
        break;

        case ' ':
        if (mf_viewedAll())
            flExit = 1, retval = READ_NEXT;
        else
            mf_forward(MFNAV_PAGE);
        break;
        case KEY_RIGHT:
        if(mf_viewedAll())
            promptend = 0, flExit = 1, retval = 0;
        else
            mf_forward(MFNAV_PAGE);
        break;

        case KEY_UP:
        if(mf_viewedNone())
            flExit = 1, retval = READ_PREV;
        else
            mf_backward(1);
        break;
        case Ctrl('H'):
        if(mf_viewedNone())
            flExit = 1, retval = READ_PREV;
        else
            mf_backward(MFNAV_PAGE);
        break;

        /* ------------------ SEARCH  KEYS ------------------ */
        case '/':
        {
            char ans[4] = "n";

            sr.search_str[0] = 0;
            getdata_buf(b_lines - 1, 0, "[搜尋]關鍵字:", sr.search_str,
                40, DOECHO);
            if (sr.search_str[0]) {
            if (getdata(b_lines - 1, 0, "區分大小寫(Y/N/Q)? [N] ",
                    ans, sizeof(ans), LCECHO) && *ans == 'y')
                sr.cmpfunc = strncmp;
            else
                sr.cmpfunc = strncasecmp;
            if (*ans == 'q')
                sr.search_str[0] = 0;
            }
            sr.len = strlen(sr.search_str);
            mf_search(MFSEARCH_FORWARD);
        }
        break;
        case 'n':
        mf_search(MFSEARCH_FORWARD);
        break;
        case 'N':
        mf_search(MFSEARCH_BACKWARD);
        break;
        /* ------------------ SPECIAL KEYS ------------------ */
        case ':':
        {
            char buf[10];
            int  i = 0;

            getdata(t_lines, 0, "Goto Page: ", buf, 5, DOECHO);
            sscanf(buf, "%d", &i);
            if(--i < 0) i = 0;
            mf_goto(i * MFNAV_PAGE);
            break;
        }
        break;

        case Ctrl('T'):
        {
            char buf[10];
            getdata(b_lines - 2, 0, "把這篇文章收入到暫存檔？[y/N] ",
                buf, 4, LCECHO);
            if (buf[0] == 'y') {
            setuserfile(buf, ask_tmpbuf(b_lines - 1));
                        Copy(fpath, buf);
            }
        }
        break;

        case 'h':
        case 'H':
        case '?':
        // help
        show_help(pmore_help);
        break;

        case 'E':
        // admin edit ve help file
        if (HAS_PERM(PERM_SYSOP) && strcmp(fpath, "etc/ve.hlp")) {
            mf_detach();
            vedit(fpath, NA, NULL);
            return 0;
        }
        break;
    }
    }

    mf_detach();
    if (retval == 0 && promptend) {
    pressanykey();
    clear();
    } else
    outs(reset_color);

    return retval;
}

/* vim:sw=4
 */