1 files changed, 102 insertions, 0 deletions
diff --git a/file_loader.c b/file_loader.c
new file mode 100644
index 0000000..b7c3817
--- /dev/null
+++ b/file_loader.c
@@ -0,0 +1,102 @@
+/*
+ * file_loader.c - Implementation of some file loading functionality.
+ */
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "file_loader.h"
+
+/*
+ * Read an entire file into memory.
+ */
+file_t *load_file(const char *filename)
+{
+    if (filename == NULL) filename = "-";
+    int fd = strcmp(filename, "-") != 0 ? open(filename, O_RDONLY) : STDIN_FILENO;
+    if (fd < 0) return NULL;
+    file_t *f = calloc(sizeof(file_t), 1);
+    f->filename = strdup(filename);
+    // TODO: use mmap when possible
+    f->mmapped = 0;
+    size_t capacity = 1000;
+    f->length = 0;
+    f->contents = calloc(sizeof(char), capacity+1);
+    ssize_t just_read;
+    while ((just_read=read(fd, &f->contents[f->length], capacity - f->length)) > 0) {
+        f->length += (size_t)just_read;
+        if (f->length >= capacity)
+            f->contents = realloc(f->contents, sizeof(char)*(capacity *= 2) + 1);
+    }
+    f->contents[f->length] = '\0';
+    close(fd);
+    
+    // Calculate line numbers:
+    size_t linecap = 10;
+    f->lines = calloc(sizeof(const char*), linecap);
+    f->nlines = 1;
+    char *p = f->contents;
+    for (size_t n = 0; p && *p; ++n) {
+        if (n >= linecap)
+            f->lines = realloc(f->lines, sizeof(const char*)*(linecap *= 2));
+        f->lines[n] = p;
+        p = strchr(p, '\n');
+        if (p) ++p;
+    }
+
+    return f;
+}
+
+void destroy_file(file_t **f)
+{
+    if ((*f)->filename) {
+        free((char*)(*f)->filename);
+        (*f)->filename = NULL;
+    }
+    if ((*f)->lines) {
+        free((*f)->lines);
+        (*f)->lines = NULL;
+    }
+    if ((*f)->contents) {
+        free((*f)->contents);
+        (*f)->contents = NULL;
+    }
+    free(*f);
+    *f = NULL;
+}
+
+size_t get_line_number(file_t *f, const char *p)
+{
+    // TODO: binary search
+    for (size_t n = 1; n < f->nlines; n++) {
+        if (f->lines[n] > p)
+            return n;
+    }
+    return 0;
+}
+
+const char *get_line(file_t *f, size_t line_number)
+{
+    if (line_number == 0 || line_number > f->nlines) return NULL;
+    return f->lines[line_number - 1];
+}
+
+void fprint_line(FILE *dest, file_t *f, const char *start, const char *end, const char *msg)
+{
+    size_t linenum = get_line_number(f, start);
+    const char *line = get_line(f, linenum);
+    size_t charnum = 1 + (size_t)(start - line);
+    fprintf(dest, "\033[1m%s:%ld:%ld:\033[0m %s\n",
+            f->filename, linenum, charnum, msg);
+    const char *eol = linenum == f->nlines ? strchr(line, '\0') : strchr(line, '\n');
+    if (end == NULL || end > eol) end = eol;
+    fprintf(dest, "\033[2m% 5ld |\033[0m %.*s\033[31;4;1m%.*s\033[0m%.*s\n",
+            linenum,
+            (int)charnum - 1, line,
+            (int)(end - &line[charnum-1]), &line[charnum-1],
+            (int)(eol - end), end);
+}