view open.cpp @ 410:d7e590d58c85 api-inversion

Pavlovian response to compiler warnings...

... attempt to squash them.  For now we can get most of the way by
writing a simple write_or_goto_error() macro for write(), and the
equivalent for read().

One of the warnings, for the return value of chdir(), is silly, because
we're already in an error case, and we really can't do anything sensible
if the chdir fails.  Try to deal with it anyway.

#include "audioDB.h"
extern "C" {
#include "audioDB_API.h"
#include "audioDB-internals.h"
}

static bool audiodb_check_header(adb_header_t *header) {
  /* FIXME: use syslog() or write to stderr or something to give the
     poor user some diagnostics. */
  if(header->magic == O2_OLD_MAGIC) {
    return false;
  }
  if(header->magic != O2_MAGIC) {
    return false;
  }
  if(header->version != O2_FORMAT_VERSION) {
    return false;
  }
  if(header->headerSize != O2_HEADERSIZE) {
    return false;
  }
  return true;
}

static int audiodb_collect_keys(adb_t *adb) {
  char *key_table = 0;
  size_t key_table_length = 0;

  if(adb->header->length > 0) {
    unsigned nfiles = adb->header->numFiles;
    key_table_length = ALIGN_PAGE_UP(nfiles * O2_FILETABLE_ENTRY_SIZE);
    mmap_or_goto_error(char *, key_table, adb->header->fileTableOffset, key_table_length);
    for (unsigned i = 0; i < nfiles; i++) {
      adb->keys->insert(key_table + i*O2_FILETABLE_ENTRY_SIZE);
    }
    munmap(key_table, key_table_length);
  }

  return 0;

 error:
  maybe_munmap(key_table, key_table_length);
  return 1;
}

adb_t *audiodb_open(const char *path, int flags) {
  adb_t *adb = 0;
  int fd = -1;

  flags &= (O_RDONLY|O_RDWR);
  fd = open(path, flags);
  if(fd == -1) {
    goto error;
  }
  if(acquire_lock(fd, flags == O_RDWR)) {
    goto error;
  }

  adb = (adb_t *) malloc(sizeof(adb_t));
  if(!adb) {
    goto error;
  }
  adb->fd = fd;
  adb->flags = flags;
  adb->path = (char *) malloc(1+strlen(path));
  if(!(adb->path)) {
    goto error;
  }
  strcpy(adb->path, path);

  adb->header = (adb_header_t *) malloc(sizeof(adb_header_t));
  if(!(adb->header)) {
    goto error;
  }
  if(read(fd, (char *) adb->header, O2_HEADERSIZE) != O2_HEADERSIZE) {
    goto error;
  }
  if(!audiodb_check_header(adb->header)) {
    goto error;
  }

  adb->keys = new std::set<std::string>;
  if(!adb->keys) {
    goto error;
  }
  if(audiodb_collect_keys(adb)) {
    goto error;
  }
  return adb;

 error:
  if(adb) {
    if(adb->header) {
      free(adb->header);
    }
    if(adb->path) {
      free(adb->path);
    }
    if(adb->keys) {
      delete adb->keys;
    }
    free(adb);
  }
  if(fd != -1) {
    close(fd);
  }
  return NULL;
}