-#include <stdio.h>
-#include <limits.h>
-#include <stdint.h>
-
-uint16_t read_uint16_bigendian(FILE * file) {
-// Read uint16 from file in big-endian order.
- const uint16_t nchar = UCHAR_MAX + 1;
- unsigned char a = fgetc(file);
- unsigned char b = fgetc(file);
- return (a * nchar) + b; }
-
-void write_uint16_bigendian(uint16_t x, FILE * file) {
-// Write uint16 to file in beg-endian order.
- const uint16_t nchar = UCHAR_MAX + 1;
- unsigned char a = x / nchar;
- unsigned char b = x % nchar;
- fputc(a, file);
- fputc(b, file); }
-
-uint32_t read_uint32_bigendian(FILE * file) {
-// Read uint32 from file in big-endian order.
- const uint16_t nchar = UCHAR_MAX + 1;
- unsigned char a = fgetc(file);
- unsigned char b = fgetc(file);
- unsigned char c = fgetc(file);
- unsigned char d = fgetc(file);
- return (a * nchar * nchar * nchar) + (b * nchar * nchar) + (c * nchar) + d; }
-
-void write_uint32_bigendian(uint32_t x, FILE * file) {
-// Write uint32 to file in beg-endian order.
- const uint16_t nchar = UCHAR_MAX + 1;
- unsigned char a = x / (nchar * nchar * nchar);
- unsigned char b = (x - (a * nchar * nchar * nchar)) / (nchar * nchar);
- unsigned char c = (x - ((a * nchar * nchar * nchar) + (b * nchar * nchar))) / nchar;
- unsigned char d = x % nchar;
- fputc(a, file);
- fputc(b, file);
- fputc(c, file);
- fputc(d, file); }
+/* readwrite.c */
+#include "readwrite.h"
+#include <stdio.h> /* for FILE typedef, fopen(), fgetc(), fputc(), fseek(),
+ * sprintf(), fwrite()
+ */
+#include <stdint.h> /* for uint8_t, uint16_t, uint32_t */
+#include <string.h> /* for strlen()*/
+#include <unistd.h> /* for unlink() */
+#include "rexit.h" /* for exit_err() */
+#include "misc.h" /* for trouble_msg() */
+struct World;
+
+
+
+/* Read/write "x" from/to "file" as bigendian representation of "size" bits. On
+ * failure, return 1, else 0. (As of of now, all extern read/write functions
+ * build on top of these.)
+ *
+ * Only use multiples of 8 greater or equal 32 for "size", so that storage
+ * inside uint32_t is possible. Originally a bit number check prefaced the code
+ * of both functions. It was removed as redundant due to all possible "size"
+ * values being hardcoded into the library (i.e. in all extern functions calling
+ * / wrapping around either function). If this ever changes, (re-)insert:
+ *
+ * if (0 == size || size > 32 || 0 != size % 8)
+ * {
+ * return 1;
+ * }
+ */
+static uint8_t read_uintX_bigendian(FILE * file, uint32_t * x, uint8_t size);
+static uint8_t write_uintX_bigendian(FILE * file, uint32_t x, uint8_t size);
+
+
+
+extern FILE * try_fopen(char * path, char * mode, struct World * w, char * f)
+{
+ char * msg1 = "Trouble in ";
+ char * msg2 = " with fopen() (mode '";
+ char * msg3 = "') on path '";
+ char * msg4 = "'.";
+ uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg3) + strlen(msg4)
+ + strlen(f) + strlen(path) + strlen(mode) + 1;
+ char msg[size];
+ sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, mode, msg3, path, msg4);
+ FILE * file_p = fopen(path, mode);
+ exit_err(NULL == file_p, w, msg);
+ return file_p;
+}
+
+
+
+extern void try_fclose(FILE * file, struct World * w, char * f)
+{
+ char * msg = trouble_msg(w, f, "fclose()");
+ exit_err(fclose(file), w, msg);
+ free(msg);
+}
+
+
+
+extern void try_fgets(char * line, int linemax, FILE * file,
+ struct World * w, char * f)
+{
+ char * msg = trouble_msg(w, f, "fgets()");
+ exit_err(NULL == fgets(line, linemax, file), w, msg);
+ free(msg);
+}
+
+
+
+extern void try_fwrite(void * ptr, size_t size, size_t nmemb, FILE * stream,
+ struct World * w, char * f)
+{
+ char * msg = trouble_msg(w, f, "fwrite()");
+ exit_err(0 == fwrite(ptr, size, nmemb, stream), w, msg);
+ free(msg);
+}
+
+
+
+extern void try_fclose_unlink_rename(FILE * file, char * p1, char * p2,
+ struct World * w, char * f)
+{
+ try_fclose(file, w, f);
+ char * msg1 = "Trouble in ";
+ char * msg4 = "'.";
+ if (!access(p2, F_OK))
+ {
+ char * msg2 = " with unlink() on path '";
+ uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg4)
+ + strlen(f) + strlen(p2) + 1;
+ char msg[size];
+ sprintf(msg, "%s%s%s%s%s", msg1, f, msg2, p2, msg4);
+ exit_err(unlink(p2), w, msg);
+ }
+ char * msg2 = " with rename() from '";
+ char * msg3 = "' to '";
+ uint16_t size = strlen(msg1) + strlen(f) + strlen(msg2) + strlen(p1)
+ + strlen(msg3) + strlen(p2) + strlen(msg4) + 1;
+ char msg[size];
+ sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, p1, msg3, p2, msg4);
+ exit_err(rename(p1, p2), w, msg);
+}
+
+
+
+extern uint16_t get_linemax(FILE * file, struct World * w, char * f)
+{
+ char * msg = trouble_msg(w, f, "textfile_sizes()");
+ uint16_t linemax;
+ exit_err(textfile_sizes(file, &linemax, NULL), w, msg);
+ free(msg);
+ return linemax;
+}
+
+
+
+extern uint8_t textfile_sizes(FILE * file, uint16_t * linemax_p,
+ uint16_t * n_lines_p)
+{
+ int c = 0;
+ uint16_t c_count = 0;
+ uint16_t n_lines = 0;
+ uint16_t linemax = 0;
+ while (1)
+ {
+ c = fgetc(file);
+ if (EOF == c)
+ {
+ break;
+ }
+ c_count++;
+ if ('\n' == c)
+ {
+ if (c_count > linemax)
+ {
+ linemax = c_count;
+ }
+ c_count = 0;
+ if (n_lines_p)
+ {
+ n_lines++;
+ }
+ }
+ }
+ if (0 == linemax && 0 < c_count) /* Handle files that consist of only one */
+ { /* line / lack newline chars. */
+ linemax = c_count;
+ }
+
+ if (-1 == fseek(file, 0, SEEK_SET))
+ {
+ return 1;
+ }
+ * linemax_p = linemax;
+ if (n_lines_p)
+ {
+ * n_lines_p = n_lines;
+ }
+ return 0;
+}
+
+
+
+static uint8_t read_uintX_bigendian(FILE * file, uint32_t * x, uint8_t size)
+{
+ * x = 0;
+ int16_t bitshift = size - 8;
+ int test;
+ for (; bitshift >= 0; bitshift = bitshift - 8)
+ {
+ test = fgetc(file);
+ if (EOF == test)
+ {
+ return 1;
+ }
+ * x = * x + ((uint32_t) test << bitshift);
+ }
+ return 0;
+}
+
+
+
+static uint8_t write_uintX_bigendian(FILE * file, uint32_t x, uint8_t size)
+{
+ int16_t bitshift = size - 8;
+ for (; bitshift >= 0; bitshift = bitshift - 8)
+ {
+ if (EOF == fputc((x >> bitshift) & 0xFF, file))
+ {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+
+
+extern uint8_t read_uint8(FILE * file, uint8_t * x)
+{
+ /* Since read_uintX_bigendian() works on -- and zeroes -- four bytes, direct
+ * work on values of fewer bytes would corrupt immediate neighbor values.
+ */
+ uint32_t y = * x;
+ uint8_t err = read_uintX_bigendian(file, &y, 8);
+ * x = (uint8_t) y;
+ return err;
+}
+
+
+
+extern uint8_t read_uint16_bigendian(FILE * file, uint16_t * x)
+{
+ /* See read_uint8() introductory code comment for rationale. */
+ uint32_t y = * x;
+ uint8_t err = read_uintX_bigendian(file, &y, 16);
+ * x = (uint16_t) y;
+ return err;
+}
+
+
+
+extern uint8_t read_uint32_bigendian(FILE * file, uint32_t * x)
+{
+ return read_uintX_bigendian(file, x, 32);
+}
+
+
+
+extern uint8_t write_uint8(uint8_t x, FILE * file)
+{
+ return write_uintX_bigendian(file, x, 8);
+}
+
+
+
+extern uint8_t write_uint16_bigendian(uint16_t x, FILE * file)
+{
+ return write_uintX_bigendian(file, x, 16);
+}
+
+
+
+extern uint8_t write_uint32_bigendian(uint32_t x, FILE * file)
+{
+ return write_uintX_bigendian(file, x, 32);
+}
projects / plomrogue / blobdiff