values.h

// Start of values.h.

//// Text I/O

typedef int (*writer)(FILE*, void*);
typedef int (*bin_reader)(void*);
typedef int (*str_reader)(const char *, void*);

struct array_reader {
  char* elems;
  int64_t n_elems_space;
  int64_t elem_size;
  int64_t n_elems_used;
  int64_t *shape;
  str_reader elem_reader;
};

static void skipspaces() {
  int c;
  do {
    c = getchar();
  } while (isspace(c));

  if (c != EOF) {
    ungetc(c, stdin);
  }
}

static int constituent(char c) {
  return isalnum(c) || c == '.' || c == '-' || c == '+' || c == '_';
}

// Produces an empty token only on EOF.
static void next_token(char *buf, int bufsize) {
 start:
  skipspaces();

  int i = 0;
  while (i < bufsize) {
    int c = getchar();
    buf[i] = (char)c;

    if (c == EOF) {
      buf[i] = 0;
      return;
    } else if (c == '-' && i == 1 && buf[0] == '-') {
      // Line comment, so skip to end of line and start over.
      for (; c != '\n' && c != EOF; c = getchar());
      goto start;
    } else if (!constituent((char)c)) {
      if (i == 0) {
        // We permit single-character tokens that are not
        // constituents; this lets things like ']' and ',' be
        // tokens.
        buf[i+1] = 0;
        return;
      } else {
        ungetc(c, stdin);
        buf[i] = 0;
        return;
      }
    }

    i++;
  }

  buf[bufsize-1] = 0;
}

static int next_token_is(char *buf, int bufsize, const char* expected) {
  next_token(buf, bufsize);
  return strcmp(buf, expected) == 0;
}

static void remove_underscores(char *buf) {
  char *w = buf;

  for (char *r = buf; *r; r++) {
    if (*r != '_') {
      *w++ = *r;
    }
  }

  *w++ = 0;
}

static int read_str_elem(char *buf, struct array_reader *reader) {
  int ret;
  if (reader->n_elems_used == reader->n_elems_space) {
    reader->n_elems_space *= 2;
    reader->elems = (char*) realloc(reader->elems,
                                    (size_t)(reader->n_elems_space * reader->elem_size));
  }

  ret = reader->elem_reader(buf, reader->elems + reader->n_elems_used * reader->elem_size);

  if (ret == 0) {
    reader->n_elems_used++;
  }

  return ret;
}

static int read_str_array_elems(char *buf, int bufsize,
                                struct array_reader *reader, int64_t dims) {
  int ret;
  int first = 1;
  char *knows_dimsize = (char*) calloc((size_t)dims, sizeof(char));
  int cur_dim = dims-1;
  int64_t *elems_read_in_dim = (int64_t*) calloc((size_t)dims, sizeof(int64_t));

  while (1) {
    next_token(buf, bufsize);

    if (strcmp(buf, "]") == 0) {
      if (knows_dimsize[cur_dim]) {
        if (reader->shape[cur_dim] != elems_read_in_dim[cur_dim]) {
          ret = 1;
          break;
        }
      } else {
        knows_dimsize[cur_dim] = 1;
        reader->shape[cur_dim] = elems_read_in_dim[cur_dim];
      }
      if (cur_dim == 0) {
        ret = 0;
        break;
      } else {
        cur_dim--;
        elems_read_in_dim[cur_dim]++;
      }
    } else if (strcmp(buf, ",") == 0) {
      next_token(buf, bufsize);
      if (strcmp(buf, "[") == 0) {
        if (cur_dim == dims - 1) {
          ret = 1;
          break;
        }
        first = 1;
        cur_dim++;
        elems_read_in_dim[cur_dim] = 0;
      } else if (cur_dim == dims - 1) {
        ret = read_str_elem(buf, reader);
        if (ret != 0) {
          break;
        }
        elems_read_in_dim[cur_dim]++;
      } else {
        ret = 1;
        break;
      }
    } else if (strlen(buf) == 0) {
      // EOF
      ret = 1;
      break;
    } else if (first) {
      if (strcmp(buf, "[") == 0) {
        if (cur_dim == dims - 1) {
          ret = 1;
          break;
        }
        cur_dim++;
        elems_read_in_dim[cur_dim] = 0;
      } else {
        ret = read_str_elem(buf, reader);
        if (ret != 0) {
          break;
        }
        elems_read_in_dim[cur_dim]++;
        first = 0;
      }
    } else {
      ret = 1;
      break;
    }
  }

  free(knows_dimsize);
  free(elems_read_in_dim);
  return ret;
}

static int read_str_empty_array(char *buf, int bufsize,
                                const char *type_name, int64_t *shape, int64_t dims) {
  if (strlen(buf) == 0) {
    // EOF
    return 1;
  }

  if (strcmp(buf, "empty") != 0) {
    return 1;
  }

  if (!next_token_is(buf, bufsize, "(")) {
    return 1;
  }

  for (int i = 0; i < dims; i++) {
    if (!next_token_is(buf, bufsize, "[")) {
      return 1;
    }

    next_token(buf, bufsize);

    if (sscanf(buf, "%"SCNu64, &shape[i]) != 1) {
      return 1;
    }

    if (!next_token_is(buf, bufsize, "]")) {
      return 1;
    }
  }

  if (!next_token_is(buf, bufsize, type_name)) {
    return 1;
  }


  if (!next_token_is(buf, bufsize, ")")) {
    return 1;
  }

  // Check whether the array really is empty.
  for (int i = 0; i < dims; i++) {
    if (shape[i] == 0) {
      return 0;
    }
  }

  // Not an empty array!
  return 1;
}

static int read_str_array(int64_t elem_size, str_reader elem_reader,
                          const char *type_name,
                          void **data, int64_t *shape, int64_t dims) {
  int ret;
  struct array_reader reader;
  char buf[100];

  int dims_seen;
  for (dims_seen = 0; dims_seen < dims; dims_seen++) {
    if (!next_token_is(buf, sizeof(buf), "[")) {
      break;
    }
  }

  if (dims_seen == 0) {
    return read_str_empty_array(buf, sizeof(buf), type_name, shape, dims);
  }

  if (dims_seen != dims) {
    return 1;
  }

  reader.shape = shape;
  reader.n_elems_used = 0;
  reader.elem_size = elem_size;
  reader.n_elems_space = 16;
  reader.elems = (char*) realloc(*data, (size_t)(elem_size*reader.n_elems_space));
  reader.elem_reader = elem_reader;

  ret = read_str_array_elems(buf, sizeof(buf), &reader, dims);

  *data = reader.elems;

  return ret;
}

#define READ_STR(MACRO, PTR, SUFFIX)                                   \
  remove_underscores(buf);                                              \
  int j;                                                                \
  if (sscanf(buf, "%"MACRO"%n", (PTR*)dest, &j) == 1) {                 \
    return !(strcmp(buf+j, "") == 0 || strcmp(buf+j, SUFFIX) == 0);     \
  } else {                                                              \
    return 1;                                                           \
  }

static int read_str_i8(char *buf, void* dest) {
  /* Some platforms (WINDOWS) does not support scanf %hhd or its
     cousin, %SCNi8.  Read into int first to avoid corrupting
     memory.

     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63417  */
  remove_underscores(buf);
  int j, x;
  if (sscanf(buf, "%i%n", &x, &j) == 1) {
    *(int8_t*)dest = (int8_t)x;
    return !(strcmp(buf+j, "") == 0 || strcmp(buf+j, "i8") == 0);
  } else {
    return 1;
  }
}

static int read_str_u8(char *buf, void* dest) {
  /* Some platforms (WINDOWS) does not support scanf %hhd or its
     cousin, %SCNu8.  Read into int first to avoid corrupting
     memory.

     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63417  */
  remove_underscores(buf);
  int j, x;
  if (sscanf(buf, "%i%n", &x, &j) == 1) {
    *(uint8_t*)dest = (uint8_t)x;
    return !(strcmp(buf+j, "") == 0 || strcmp(buf+j, "u8") == 0);
  } else {
    return 1;
  }
}

static int read_str_i16(char *buf, void* dest) {
  READ_STR(SCNi16, int16_t, "i16");
}

static int read_str_u16(char *buf, void* dest) {
  READ_STR(SCNi16, int16_t, "u16");
}

static int read_str_i32(char *buf, void* dest) {
  READ_STR(SCNi32, int32_t, "i32");
}

static int read_str_u32(char *buf, void* dest) {
  READ_STR(SCNi32, int32_t, "u32");
}

static int read_str_i64(char *buf, void* dest) {
  READ_STR(SCNi64, int64_t, "i64");
}

static int read_str_u64(char *buf, void* dest) {
  // FIXME: This is not correct, as SCNu64 only permits decimal
  // literals.  However, SCNi64 does not handle very large numbers
  // correctly (it's really for signed numbers, so that's fair).
  READ_STR(SCNu64, uint64_t, "u64");
}

static int read_str_f32(char *buf, void* dest) {
  remove_underscores(buf);
  if (strcmp(buf, "f32.nan") == 0) {
    *(float*)dest = NAN;
    return 0;
  } else if (strcmp(buf, "f32.inf") == 0) {
    *(float*)dest = INFINITY;
    return 0;
  } else if (strcmp(buf, "-f32.inf") == 0) {
    *(float*)dest = -INFINITY;
    return 0;
  } else {
    READ_STR("f", float, "f32");
  }
}

static int read_str_f64(char *buf, void* dest) {
  remove_underscores(buf);
  if (strcmp(buf, "f64.nan") == 0) {
    *(double*)dest = NAN;
    return 0;
  } else if (strcmp(buf, "f64.inf") == 0) {
    *(double*)dest = INFINITY;
    return 0;
  } else if (strcmp(buf, "-f64.inf") == 0) {
    *(double*)dest = -INFINITY;
    return 0;
  } else {
    READ_STR("lf", double, "f64");
  }
}

static int read_str_bool(char *buf, void* dest) {
  if (strcmp(buf, "true") == 0) {
    *(char*)dest = 1;
    return 0;
  } else if (strcmp(buf, "false") == 0) {
    *(char*)dest = 0;
    return 0;
  } else {
    return 1;
  }
}

static int write_str_i8(FILE *out, int8_t *src) {
  return fprintf(out, "%hhdi8", *src);
}

static int write_str_u8(FILE *out, uint8_t *src) {
  return fprintf(out, "%hhuu8", *src);
}

static int write_str_i16(FILE *out, int16_t *src) {
  return fprintf(out, "%hdi16", *src);
}

static int write_str_u16(FILE *out, uint16_t *src) {
  return fprintf(out, "%huu16", *src);
}

static int write_str_i32(FILE *out, int32_t *src) {
  return fprintf(out, "%di32", *src);
}

static int write_str_u32(FILE *out, uint32_t *src) {
  return fprintf(out, "%uu32", *src);
}

static int write_str_i64(FILE *out, int64_t *src) {
  return fprintf(out, "%"PRIi64"i64", *src);
}

static int write_str_u64(FILE *out, uint64_t *src) {
  return fprintf(out, "%"PRIu64"u64", *src);
}

static int write_str_f32(FILE *out, float *src) {
  float x = *src;
  if (isnan(x)) {
    return fprintf(out, "f32.nan");
  } else if (isinf(x) && x >= 0) {
    return fprintf(out, "f32.inf");
  } else if (isinf(x)) {
    return fprintf(out, "-f32.inf");
  } else {
    return fprintf(out, "%.6ff32", x);
  }
}

static int write_str_f64(FILE *out, double *src) {
  double x = *src;
  if (isnan(x)) {
    return fprintf(out, "f64.nan");
  } else if (isinf(x) && x >= 0) {
    return fprintf(out, "f64.inf");
  } else if (isinf(x)) {
    return fprintf(out, "-f64.inf");
  } else {
    return fprintf(out, "%.6ff64", *src);
  }
}

static int write_str_bool(FILE *out, void *src) {
  return fprintf(out, *(char*)src ? "true" : "false");
}

//// Binary I/O

#define BINARY_FORMAT_VERSION 2
#define IS_BIG_ENDIAN (!*(unsigned char *)&(uint16_t){1})

static void flip_bytes(int elem_size, unsigned char *elem) {
  for (int j=0; j<elem_size/2; j++) {
    unsigned char head = elem[j];
    int tail_index = elem_size-1-j;
    elem[j] = elem[tail_index];
    elem[tail_index] = head;
  }
}

// On Windows we need to explicitly set the file mode to not mangle
// newline characters.  On *nix there is no difference.
#ifdef _WIN32
#include <io.h>
#include <fcntl.h>
static void set_binary_mode(FILE *f) {
  setmode(fileno(f), O_BINARY);
}
#else
static void set_binary_mode(FILE *f) {
  (void)f;
}
#endif

static int read_byte(void* dest) {
  int num_elems_read = fread(dest, 1, 1, stdin);
  return num_elems_read == 1 ? 0 : 1;
}

//// Types

struct primtype_info_t {
  const char binname[4]; // Used for parsing binary data.
  const char* type_name; // Same name as in Futhark.
  const int64_t size; // in bytes
  const writer write_str; // Write in text format.
  const str_reader read_str; // Read in text format.
};

static const struct primtype_info_t i8_info =
  {.binname = "  i8", .type_name = "i8",   .size = 1,
   .write_str = (writer)write_str_i8, .read_str = (str_reader)read_str_i8};
static const struct primtype_info_t i16_info =
  {.binname = " i16", .type_name = "i16",  .size = 2,
   .write_str = (writer)write_str_i16, .read_str = (str_reader)read_str_i16};
static const struct primtype_info_t i32_info =
  {.binname = " i32", .type_name = "i32",  .size = 4,
   .write_str = (writer)write_str_i32, .read_str = (str_reader)read_str_i32};
static const struct primtype_info_t i64_info =
  {.binname = " i64", .type_name = "i64",  .size = 8,
   .write_str = (writer)write_str_i64, .read_str = (str_reader)read_str_i64};
static const struct primtype_info_t u8_info =
  {.binname = "  u8", .type_name = "u8",   .size = 1,
   .write_str = (writer)write_str_u8, .read_str = (str_reader)read_str_u8};
static const struct primtype_info_t u16_info =
  {.binname = " u16", .type_name = "u16",  .size = 2,
   .write_str = (writer)write_str_u16, .read_str = (str_reader)read_str_u16};
static const struct primtype_info_t u32_info =
  {.binname = " u32", .type_name = "u32",  .size = 4,
   .write_str = (writer)write_str_u32, .read_str = (str_reader)read_str_u32};
static const struct primtype_info_t u64_info =
  {.binname = " u64", .type_name = "u64",  .size = 8,
   .write_str = (writer)write_str_u64, .read_str = (str_reader)read_str_u64};
static const struct primtype_info_t f32_info =
  {.binname = " f32", .type_name = "f32",  .size = 4,
   .write_str = (writer)write_str_f32, .read_str = (str_reader)read_str_f32};
static const struct primtype_info_t f64_info =
  {.binname = " f64", .type_name = "f64",  .size = 8,
   .write_str = (writer)write_str_f64, .read_str = (str_reader)read_str_f64};
static const struct primtype_info_t bool_info =
  {.binname = "bool", .type_name = "bool", .size = 1,
   .write_str = (writer)write_str_bool, .read_str = (str_reader)read_str_bool};

static const struct primtype_info_t* primtypes[] = {
  &i8_info, &i16_info, &i32_info, &i64_info,
  &u8_info, &u16_info, &u32_info, &u64_info,
  &f32_info, &f64_info,
  &bool_info,
  NULL // NULL-terminated
};

// General value interface.  All endian business taken care of at
// lower layers.

static int read_is_binary() {
  skipspaces();
  int c = getchar();
  if (c == 'b') {
    int8_t bin_version;
    int ret = read_byte(&bin_version);

    if (ret != 0) { panic(1, "binary-input: could not read version.\n"); }

    if (bin_version != BINARY_FORMAT_VERSION) {
      panic(1, "binary-input: File uses version %i, but I only understand version %i.\n",
            bin_version, BINARY_FORMAT_VERSION);
    }

    return 1;
  }
  ungetc(c, stdin);
  return 0;
}

static const struct primtype_info_t* read_bin_read_type_enum() {
  char read_binname[4];

  int num_matched = scanf("%4c", read_binname);
  if (num_matched != 1) { panic(1, "binary-input: Couldn't read element type.\n"); }

  const struct primtype_info_t **type = primtypes;

  for (; *type != NULL; type++) {
    // I compare the 4 characters manually instead of using strncmp because
    // this allows any value to be used, also NULL bytes
    if (memcmp(read_binname, (*type)->binname, 4) == 0) {
      return *type;
    }
  }
  panic(1, "binary-input: Did not recognize the type '%s'.\n", read_binname);
  return NULL;
}

static void read_bin_ensure_scalar(const struct primtype_info_t *expected_type) {
  int8_t bin_dims;
  int ret = read_byte(&bin_dims);
  if (ret != 0) { panic(1, "binary-input: Couldn't get dims.\n"); }

  if (bin_dims != 0) {
    panic(1, "binary-input: Expected scalar (0 dimensions), but got array with %i dimensions.\n",
          bin_dims);
  }

  const struct primtype_info_t *bin_type = read_bin_read_type_enum();
  if (bin_type != expected_type) {
    panic(1, "binary-input: Expected scalar of type %s but got scalar of type %s.\n",
          expected_type->type_name,
          bin_type->type_name);
  }
}

//// High-level interface

static int read_bin_array(const struct primtype_info_t *expected_type, void **data, int64_t *shape, int64_t dims) {
  int ret;

  int8_t bin_dims;
  ret = read_byte(&bin_dims);
  if (ret != 0) { panic(1, "binary-input: Couldn't get dims.\n"); }

  if (bin_dims != dims) {
    panic(1, "binary-input: Expected %i dimensions, but got array with %i dimensions.\n",
          dims, bin_dims);
  }

  const struct primtype_info_t *bin_primtype = read_bin_read_type_enum();
  if (expected_type != bin_primtype) {
    panic(1, "binary-input: Expected %iD-array with element type '%s' but got %iD-array with element type '%s'.\n",
          dims, expected_type->type_name, dims, bin_primtype->type_name);
  }

  int64_t elem_count = 1;
  for (int i=0; i<dims; i++) {
    int64_t bin_shape;
    ret = fread(&bin_shape, sizeof(bin_shape), 1, stdin);
    if (ret != 1) {
      panic(1, "binary-input: Couldn't read size for dimension %i of array.\n", i);
    }
    if (IS_BIG_ENDIAN) {
      flip_bytes(sizeof(bin_shape), (unsigned char*) &bin_shape);
    }
    elem_count *= bin_shape;
    shape[i] = bin_shape;
  }

  int64_t elem_size = expected_type->size;
  void* tmp = realloc(*data, (size_t)(elem_count * elem_size));
  if (tmp == NULL) {
    panic(1, "binary-input: Failed to allocate array of size %i.\n",
          elem_count * elem_size);
  }
  *data = tmp;

  int64_t num_elems_read = (int64_t)fread(*data, (size_t)elem_size, (size_t)elem_count, stdin);
  if (num_elems_read != elem_count) {
    panic(1, "binary-input: tried to read %i elements of an array, but only got %i elements.\n",
          elem_count, num_elems_read);
  }

  // If we're on big endian platform we must change all multibyte elements
  // from using little endian to big endian
  if (IS_BIG_ENDIAN && elem_size != 1) {
    flip_bytes(elem_size, (unsigned char*) *data);
  }

  return 0;
}

static int read_array(const struct primtype_info_t *expected_type, void **data, int64_t *shape, int64_t dims) {
  if (!read_is_binary()) {
    return read_str_array(expected_type->size, (str_reader)expected_type->read_str, expected_type->type_name, data, shape, dims);
  } else {
    return read_bin_array(expected_type, data, shape, dims);
  }
}

static int end_of_input() {
  skipspaces();
  char token[2];
  next_token(token, sizeof(token));
  if (strcmp(token, "") == 0) {
    return 0;
  } else {
    return 1;
  }
}

static int write_str_array(FILE *out, const struct primtype_info_t *elem_type, unsigned char *data, int64_t *shape, int8_t rank) {
  if (rank==0) {
    elem_type->write_str(out, (void*)data);
  } else {
    int64_t len = (int64_t)shape[0];
    int64_t slice_size = 1;

    int64_t elem_size = elem_type->size;
    for (int8_t i = 1; i < rank; i++) {
      slice_size *= shape[i];
    }

    if (len*slice_size == 0) {
      printf("empty(");
      for (int64_t i = 0; i < rank; i++) {
        printf("[%"PRIi64"]", shape[i]);
      }
      printf("%s", elem_type->type_name);
      printf(")");
    } else if (rank==1) {
      putchar('[');
      for (int64_t i = 0; i < len; i++) {
        elem_type->write_str(out, (void*) (data + i * elem_size));
        if (i != len-1) {
          printf(", ");
        }
      }
      putchar(']');
    } else {
      putchar('[');
      for (int64_t i = 0; i < len; i++) {
        write_str_array(out, elem_type, data + i * slice_size * elem_size, shape+1, rank-1);
        if (i != len-1) {
          printf(", ");
        }
      }
      putchar(']');
    }
  }
  return 0;
}

static int write_bin_array(FILE *out, const struct primtype_info_t *elem_type, unsigned char *data, int64_t *shape, int8_t rank) {
  int64_t num_elems = 1;
  for (int64_t i = 0; i < rank; i++) {
    num_elems *= shape[i];
  }

  fputc('b', out);
  fputc((char)BINARY_FORMAT_VERSION, out);
  fwrite(&rank, sizeof(int8_t), 1, out);
  fputs(elem_type->binname, out);
  if (shape != NULL) {
    fwrite(shape, sizeof(int64_t), (size_t)rank, out);
  }

  if (IS_BIG_ENDIAN) {
    for (int64_t i = 0; i < num_elems; i++) {
      unsigned char *elem = data+i*elem_type->size;
      for (int64_t j = 0; j < elem_type->size; j++) {
        fwrite(&elem[elem_type->size-j], 1, 1, out);
      }
    }
  } else {
    fwrite(data, (size_t)elem_type->size, (size_t)num_elems, out);
  }

  return 0;
}

static int write_array(FILE *out, int write_binary,
                       const struct primtype_info_t *elem_type, void *data, int64_t *shape, int8_t rank) {
  if (write_binary) {
    return write_bin_array(out, elem_type, data, shape, rank);
  } else {
    return write_str_array(out, elem_type, data, shape, rank);
  }
}

static int read_scalar(const struct primtype_info_t *expected_type, void *dest) {
  if (!read_is_binary()) {
    char buf[100];
    next_token(buf, sizeof(buf));
    return expected_type->read_str(buf, dest);
  } else {
    read_bin_ensure_scalar(expected_type);
    int64_t elem_size = expected_type->size;
    int num_elems_read = fread(dest, (size_t)elem_size, 1, stdin);
    if (IS_BIG_ENDIAN) {
      flip_bytes(elem_size, (unsigned char*) dest);
    }
    return num_elems_read == 1 ? 0 : 1;
  }
}

static int write_scalar(FILE *out, int write_binary, const struct primtype_info_t *type, void *src) {
  if (write_binary) {
    return write_bin_array(out, type, src, NULL, 0);
  } else {
    return type->write_str(out, src);
  }
}

// End of values.h.