Isolate the grotty save/resume code. Most of it will soon go away.

This commit is contained in:
Eric S. Raymond 2017-06-10 05:38:47 -04:00
parent 4c5474121f
commit 3af993abca
5 changed files with 230 additions and 222 deletions

122
misc.c
View file

@ -8,9 +8,6 @@
#include "database.h"
#include "linenoise/linenoise.h"
/* hack to ignore GCC Unused Result */
#define IGNORE(r) do{if (r){}}while(0)
#define PERCENT 63 /* partly hide the packed encoding */
const char advent_to_ascii[] = {0, 32, 33, 34, 39, 40, 41, 42, 43, 44, 45, 46, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 37, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 35, 36, 38, 47, 58, 59, 60, 61, 62, 63, 64, 91, 92, 93, 94, 95, 96, 123, 124, 125, 126, 0};
@ -382,91 +379,6 @@ void TYPE0(void)
return;
}
/* Suspend/resume I/O routines (SAVWDS, SAVARR, SAVWRD) */
void fSAVWDS(long *W1, long *W2, long *W3, long *W4,
long *W5, long *W6, long *W7)
/* Write or read 7 variables. See SAVWRD. */
{
SAVWRD(0,(*W1));
SAVWRD(0,(*W2));
SAVWRD(0,(*W3));
SAVWRD(0,(*W4));
SAVWRD(0,(*W5));
SAVWRD(0,(*W6));
SAVWRD(0,(*W7));
}
void fSAVARR(long arr[], long n)
/* Write or read an array of n words. See SAVWRD. */
{
long i;
for (i=1; i<=n; i++) {
SAVWRD(0,arr[i]);
}
return;
}
void fSAVWRD(long op, long *pword)
/* If OP<0, start writing a file, using word to initialise encryption; save
* word in the file. If OP>0, start reading a file; read the file to find
* the value with which to decrypt the rest. In either case, if a file is
* already open, finish writing/reading it and don't start a new one. If OP=0,
* read/write a single word. Words are buffered in case that makes for more
* efficient disk use. We also compute a simple checksum to catch elementary
* poking within the saved file. When we finish reading/writing the file,
* we store zero into *PWORD if there's no checksum error, else nonzero. */
{
static long buf[250], cksum = 0, h1, hash = 0, n = 0, state = 0;
if (op != 0)
{
long ifvar = state;
switch (ifvar<0 ? -1 : (ifvar>0 ? 1 : 0))
{
case -1:
case 1:
if (n == 250)SAVEIO(1,state > 0,buf);
n=MOD(n,250)+1;
if (state <= 0) {
n--; buf[n]=cksum; n++;
SAVEIO(1,false,buf);
}
n--; *pword=buf[n]-cksum; n++;
SAVEIO(-1,state > 0,buf);
state=0;
break;
case 0: /* FIXME: Huh? should be impossible */
state=op;
SAVEIO(0,state > 0,buf);
n=1;
if (state <= 0) {
hash=MOD(*pword,1048576L);
buf[0]=1234L*5678L-hash;
}
SAVEIO(1,true,buf);
hash=MOD(1234L*5678L-buf[0],1048576L);
cksum=buf[0];
return;
}
}
if (state == 0)
return;
if (n == 250)
SAVEIO(1,state > 0,buf);
n=MOD(n,250)+1;
h1=MOD(hash*1093L+221573L,1048576L);
hash=MOD(h1*1093L+221573L,1048576L);
h1=MOD(h1,1234)*765432+MOD(hash,123);
n--;
if (state > 0)
*pword=buf[n]+h1;
buf[n]=*pword-h1;
n++;
cksum=MOD(cksum*13+*pword,1000000000L);
}
/* Data structure routines */
long VOCAB(long id, long init)
@ -790,40 +702,6 @@ void TYPE(void)
return;
}
void fSAVEIO(long op, long in, long arr[])
/* If OP=0, ask for a file name and open a file. (If IN=true, the file is for
* input, else output.) If OP>0, read/write ARR from/into the previously-opened
* file. (ARR is a 250-integer array.) If OP<0, finish reading/writing the
* file. (Finishing writing can be a no-op if a "stop" statement does it
* automatically. Finishing reading can be a no-op as long as a subsequent
* SAVEIO(0,false,X) will still work.) */
{
static FILE *fp = NULL;
char* name;
switch (op < 0 ? -1 : (op > 0 ? 1 : 0))
{
case -1:
fclose(fp);
break;
case 0:
while (fp == NULL) {
name = linenoise("File name: ");
fp = fopen(name,(in ? READ_MODE : WRITE_MODE));
if (fp == NULL)
printf("Can't open file %s, try again.\n", name);
}
linenoiseFree(name);
break;
case 1:
if (in)
IGNORE(fread(arr,sizeof(long),250,fp));
else
IGNORE(fwrite(arr,sizeof(long),250,fp));
break;
}
}
void DATIME(long* d, long* t)
{
struct timeval tv;