Update

file_reader.c

@@ -0,0 +1,136 @@
+#include "file_reader.h"
+
+#include <malloc.h>
+#include <stdio.h>
+#include "cfileop.h"
+#include "cstr_util.h"
+
+typedef struct file_reader_file {
+    FILE* f;
+    /// 0 if little endian otherwise big endian
+    unsigned char endian;
+} file_reader_file;
+
+file_reader_file* create_file_reader(FILE* f, unsigned char endian) {
+    if (!f) return NULL;
+    file_reader_file* r = malloc(sizeof(file_reader_file));
+    if (!r) return NULL;
+    r->f = f;
+    r->endian = endian;
+    return r;
+}
+
+void free_file_reader(file_reader_file* f) {
+    if (!f) return;
+    free(f);
+}
+
+void set_file_reader_endian(file_reader_file* f, unsigned char endian) {
+    if (!f) return;
+    f->endian = endian;
+}
+
+int file_reader_read_int32(file_reader_file* f, int32_t* re) {
+    if (!f) return 1;
+    int64_t offset = fileop_ftell(f->f);
+    int32_t r = 0;
+    int origin = SEEK_SET;
+    if (offset == -1) {
+        origin = SEEK_CUR;
+    }
+    size_t c;
+    uint8_t buf[4];
+    if ((c = fread(buf, 1, 4, f->f)) < 4) {
+        if (origin == SEEK_CUR) offset = -c;
+        fileop_fseek(f->f, offset, origin);
+        return 1;
+    }
+    r = cstr_read_int32(buf, f->endian);
+    if (re) *re = r;
+    return 0;
+}
+
+int file_reader_read_uint32(file_reader_file* f, uint32_t* re) {
+    return file_reader_read_int32(f, (int32_t*)re);
+}
+
+int file_reader_read_int64(file_reader_file* f, int64_t* re) {
+    if (!f) return 1;
+    int64_t offset = fileop_ftell(f->f), r = 0;
+    int origin = SEEK_SET;
+    if (offset == -1) {
+        origin = SEEK_CUR;
+    }
+    size_t c;
+    uint8_t buf[8];
+    if ((c = fread(buf, 1, 8, f->f)) < 8) {
+        if (origin == SEEK_CUR) offset = -c;
+        fileop_fseek(f->f, offset, origin);
+        return 1;
+    }
+    r = cstr_read_int64(buf, f->endian);
+    if (re) *re = r;
+    return 0;
+}
+
+int file_reader_read_str(file_reader_file* f, char** buf) {
+    if (!f) return 1;
+    char* b = NULL;
+    char bu[128];
+    size_t blen = 128, n = 0, c = 0, tc = 0, pos = 0;
+    if (buf) {
+        b = malloc(blen);
+        if (!b) return 1;
+    }
+    int64_t offset = fileop_ftell(f->f);
+    int origin = SEEK_SET;
+    if (offset == -1) {
+        origin = SEEK_CUR;
+    }
+    while (1) {
+        if (n >= c) {
+            if (!(tc = fread(bu, 1, 128, f->f))) {
+                if (b) free(b);
+                if (origin == SEEK_CUR) {
+                    offset = -c;
+                }
+                fileop_fseek(f->f, offset, origin);
+                return 1;
+            }
+            c += tc;
+        }
+        if (buf && n >= blen) {
+            size_t nlen = blen + 128;
+            char* nb = realloc(b, nlen);
+            if (!nb) {
+                if (b) free(b);
+                if (origin == SEEK_CUR) {
+                    offset = -c;
+                }
+                fileop_fseek(f->f, offset, origin);
+                return 1;
+            }
+            b = nb;
+            blen = nlen;
+        }
+        pos = n - (c - tc);
+        if (buf && b) {
+            b[n] = bu[pos];
+        }
+        if (bu[pos] == 0) {
+            break;
+        }
+        n++;
+    }
+    if (buf) {
+        char* nb = realloc(b, n + 1);
+        *buf = nb ? nb : b;
+    }
+    if (origin == SEEK_SET) {
+        offset += n + 1;
+    } else {
+        offset = -(c - n - 1);
+    }
+    fileop_fseek(f->f, offset, origin);
+    return 0;
+}