Initial commit

src/file_stream.c

@@ -0,0 +1,110 @@
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "error.h"
+#include "file_stream.h"
+
+char* mfile_overflow_slope = NULL;
+
+Mfile* mfile_open(Error* err, char* filename)
+{
+	Mfile* s = malloc(sizeof *s);
+	if (!s) {
+		error_push(err, "failed to allocate file stream struct: %s", strerror(errno));
+        goto malloc_fail;
+	}
+
+	s->fd = open(filename, O_RDONLY);
+	if (s->fd == -1) {
+		error_push(err, "failed to open file %s: %s", filename, strerror(errno));
+        goto open_fail;
+	}
+
+	struct stat sb;
+	int ok = fstat(s->fd, &sb);
+	if (ok == -1) {
+		error_push(err, "failed to stat file %s: %s", filename, strerror(errno));
+        goto stat_fail;
+	}
+	s->size = sb.st_size;
+
+	s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, s->fd, 0);
+	if (s->data == MAP_FAILED) {
+		error_push(err, "failed to mmap file: %s", strerror(errno));
+        goto mmap_fail;
+	}
+
+    return s;
+
+mmap_fail:
+stat_fail:
+    close(s->fd);
+open_fail:
+    free(s);
+malloc_fail:
+    return NULL;
+}
+
+void mfile_close(Error* err, Mfile* s)
+{
+    int ok;
+    ok = munmap(s->data, s->size);
+    if (ok == -1) {
+        error_push(err, "failed to munmap file: %s", strerror(errno));
+        free(s);
+        return;
+    }
+    close(s->fd);
+    if (ok == -1) {
+        error_push(err, "failed to close file: %s", strerror(errno));
+        free(s);
+        return;
+    }
+    free(s);
+}
+
+int mfile_get(Mfile* s)
+{
+    if (s->pos >= s->size) {
+        return EOF;
+    }
+    return s->data[s->pos++];
+}
+
+bool mfile_eof(Mfile* s)
+{
+    return s->pos >= s->size;
+}
+
+char* mfile_cur(Mfile* s)
+{
+    if (s->pos >= s->size) {
+        return mfile_overflow_slope;
+    }
+    return s->data + s->pos;
+}
+
+int mfile_curchar(Mfile* s)
+{
+    if (s->pos >= s->size) {
+        return EOF;
+    }
+    return *(s->data + s->pos);
+}
+
+void mfile_skip(Mfile* s, int (*f)(int))
+{
+    while (f(*(s->data + s->pos)))
+        s->pos += 1;
+}
+
+
+
+