Replace EFF_RDONLY by EFF_PRIVATE

Read-only was a bit of a misnomer: you could write to the table by
obtaining a pointer into it from ef_ptr(), you just couldn't write to
the backing file.

Semantic changes:

* ef_flush() is now allowed when the table is file-backed or privately
  mapped.  Before, it had to be file-backed.  Flushing a privately
  mapped table does nothing, just like flushing a read-only table did.

* ef_write() is now allowed when the table is file-backed or fully
  cached.  Before, it had to be file-backed and not read-only.
  Writing to a privately mapped file-backed table doesn't write to the
  file.

* ef_extend() is not implemented for privately mapped tables, just
  like it wasn't implemented for read-only tables.

diff --git a/include/file.h b/include/file.h
index 6748ba78a682a7b05333fc04560a1bcd519ebf87..1242a660f928b5ff2bf045bcc8dd32b043750b18 100644 (file)
--- a/include/file.h
+++ b/include/file.h
@@ -57,7 +57,7 @@ struct empfile {
     int cids;                  /* # entries in cache */
     int fids;                  /* # entries in table */
     int fd;                    /* file descriptor, -1 if not open */
     int cids;                  /* # entries in cache */
     int fids;                  /* # entries in table */
     int fd;                    /* file descriptor, -1 if not open */

-    /* flags bits EFF_RDONLY, EFF_CUSTOM also vary */
+    /* flags bits EFF_PRIVATE, EFF_CUSTOM also vary */

 
     /* User callbacks */
     void (*init)(int, void *); /* called after entry creation, unless null */
 
     /* User callbacks */
     void (*init)(int, void *); /* called after entry creation, unless null */


@@ -86,8 +86,8 @@ struct empfile {
 /* Flags set when table contents is mapped */
 /* Table is entirely in memory */
 #define EFF_MEM                bit(8)
 /* Flags set when table contents is mapped */
 /* Table is entirely in memory */
 #define EFF_MEM                bit(8)

-/* Table is read-only */
-#define EFF_RDONLY     bit(9)
+/* Table is privately mapped: changes don't affect the underlying file */
+#define EFF_PRIVATE    bit(9)

 /* Table is customized (configuration tables only) */
 #define EFF_CUSTOM     bit(10)
 /* Transient flags, only occur in argument of ef_open() */
 /* Table is customized (configuration tables only) */
 #define EFF_CUSTOM     bit(10)
 /* Transient flags, only occur in argument of ef_open() */


@@ -97,7 +97,8 @@ struct empfile {
 /*
  * Empire `file types'
  * These are really table IDs.  Some tables are backed by files, some
 /*
  * Empire `file types'
  * These are really table IDs.  Some tables are backed by files, some

- * are compiled into the server.
+ * are compiled into the server, some initialized from configuration
+ * files.

  */
 enum {
     /* Error value */
  */
 enum {
     /* Error value */

diff --git a/src/lib/common/file.c b/src/lib/common/file.c
index ebf5ab259c8aec45c196fe17c083ce5f02c89dc8..a4f728591262373465ad56cfbd75b30165ef3827 100644 (file)
--- a/src/lib/common/file.c
+++ b/src/lib/common/file.c
@@ -73,7 +73,7 @@ ef_open(int type, int how)
     if (CANT_HAPPEN(ep->fd >= 0))
        return 0;
     oflags = O_RDWR;
     if (CANT_HAPPEN(ep->fd >= 0))
        return 0;
     oflags = O_RDWR;

-    if (how & EFF_RDONLY)
+    if (how & EFF_PRIVATE)

        oflags = O_RDONLY;
     if (how & EFF_CREATE)
        oflags |= O_CREAT | O_TRUNC;
        oflags = O_RDONLY;
     if (how & EFF_CREATE)
        oflags |= O_CREAT | O_TRUNC;


@@ -85,7 +85,7 @@ ef_open(int type, int how)
        return 0;
     }
 
        return 0;
     }
 

-    lock.l_type = how & EFF_RDONLY ? F_RDLCK : F_WRLCK;
+    lock.l_type = how & EFF_PRIVATE ? F_RDLCK : F_WRLCK;

     lock.l_whence = SEEK_SET;
     lock.l_start = lock.l_len = 0;
     if (fcntl(fd, F_SETLK, &lock) == -1) {
     lock.l_whence = SEEK_SET;
     lock.l_start = lock.l_len = 0;
     if (fcntl(fd, F_SETLK, &lock) == -1) {


@@ -177,7 +177,8 @@ ef_close(int type)
 }
 
 /*
 }
 
 /*

- * Flush file-backed table TYPE (EF_SECTOR, ...) to disk.
+ * Flush table TYPE (EF_SECTOR, ...) to disk.
+ * Does nothing if the table is privately mapped.

  * Return non-zero on success, zero on failure.
  */
 int
  * Return non-zero on success, zero on failure.
  */
 int


@@ -188,6 +189,8 @@ ef_flush(int type)
     if (ef_check(type) < 0)
        return 0;
     ep = &empfile[type];
     if (ef_check(type) < 0)
        return 0;
     ep = &empfile[type];

+    if (ep->flags & EFF_PRIVATE)
+       return 1;               /* nothing to do */

     if (CANT_HAPPEN(ep->fd < 0))
        return 0;
     /*
     if (CANT_HAPPEN(ep->fd < 0))
        return 0;
     /*


@@ -196,7 +199,7 @@ ef_flush(int type)
      * allowed only with EFF_MEM.  Assume the whole cash is dirty
      * then.
      */
      * allowed only with EFF_MEM.  Assume the whole cash is dirty
      * then.
      */

-    if (!(ep->flags & EFF_RDONLY) && (ep->flags & EFF_MEM))
+    if (ep->flags & EFF_MEM)

        return do_write(ep, ep->cache, ep->baseid, ep->cids) >= 0;
 
     return 1;
        return do_write(ep, ep->cache, ep->baseid, ep->cids) >= 0;
 
     return 1;


@@ -311,7 +314,8 @@ do_write(struct empfile *ep, void *buf, int id, int count)
     int n, ret;
     char *p;
 
     int n, ret;
     char *p;
 

-    if (CANT_HAPPEN(ep->fd < 0 || id < 0 || count < 0))
+    if (CANT_HAPPEN(ep->fd < 0 || (ep->flags & EFF_PRIVATE)
+                   || id < 0 || count < 0))

        return -1;
 
     if (lseek(ep->fd, id * ep->size, SEEK_SET) == (off_t)-1) {
        return -1;
 
     if (lseek(ep->fd, id * ep->size, SEEK_SET) == (off_t)-1) {


@@ -339,9 +343,10 @@ do_write(struct empfile *ep, void *buf, int id, int count)
 }
 
 /*
 }
 
 /*

- * Write element ID into file-backed table TYPE from buffer FROM.
+ * Write element ID into table TYPE from buffer FROM.

  * FIXME pass buffer size!
  * FIXME pass buffer size!

- * Write through cache straight to disk.
+ * If table is file-backed and not privately mapped, write through
+ * cache straight to disk.

  * Cannot write beyond the end of fully cached table (flags & EFF_MEM).
  * Can write at the end of partially cached table.
  * Return non-zero on success, zero on failure.
  * Cannot write beyond the end of fully cached table (flags & EFF_MEM).
  * Can write at the end of partially cached table.
  * Return non-zero on success, zero on failure.


@@ -355,12 +360,16 @@ ef_write(int type, int id, void *from)
     if (ef_check(type) < 0)
        return 0;
     ep = &empfile[type];
     if (ef_check(type) < 0)
        return 0;
     ep = &empfile[type];

+    if (CANT_HAPPEN((ep->flags & (EFF_MEM | EFF_PRIVATE)) == EFF_PRIVATE))
+       return 0;

     if (ep->prewrite)
        ep->prewrite(id, from);
     if (CANT_HAPPEN((ep->flags & EFF_MEM) ? id >= ep->fids : id > ep->fids))
        return 0;               /* not implemented */
     if (ep->prewrite)
        ep->prewrite(id, from);
     if (CANT_HAPPEN((ep->flags & EFF_MEM) ? id >= ep->fids : id > ep->fids))
        return 0;               /* not implemented */

-    if (do_write(ep, from, id, 1) < 0)
-       return 0;
+    if (!(ep->flags & EFF_PRIVATE)) {
+       if (do_write(ep, from, id, 1) < 0)
+           return 0;
+    }

     if (id >= ep->baseid && id < ep->baseid + ep->cids) {
        /* update the cache if necessary */
        to = ep->cache + (id - ep->baseid) * ep->size;
     if (id >= ep->baseid && id < ep->baseid + ep->cids) {
        /* update the cache if necessary */
        to = ep->cache + (id - ep->baseid) * ep->size;


@@ -376,6 +385,7 @@ ef_write(int type, int id, void *from)
 
 /*
  * Extend the file-backed table TYPE by COUNT elements.
 
 /*
  * Extend the file-backed table TYPE by COUNT elements.

+ * Can't extend privately mapped tables.

  * Return non-zero on success, zero on failure.
  */
 int
  * Return non-zero on success, zero on failure.
  */
 int


@@ -390,6 +400,8 @@ ef_extend(int type, int count)
     ep = &empfile[type];
     if (CANT_HAPPEN(ep->fd < 0 || count < 0))
        return 0;
     ep = &empfile[type];
     if (CANT_HAPPEN(ep->fd < 0 || count < 0))
        return 0;

+    if (CANT_HAPPEN(ep->flags & EFF_PRIVATE))
+       return 0;               /* not implemented */

 
     tmpobj = calloc(1, ep->size);
     id = ep->fids;
 
     tmpobj = calloc(1, ep->size);
     id = ep->fids;

diff --git a/src/lib/global/file.c b/src/lib/global/file.c
index 51e28dc1170f41308a0db2c92052e993af0ff200..9db598fc090d74194d1b5c26e99ca9e717677d18 100644 (file)
--- a/src/lib/global/file.c
+++ b/src/lib/global/file.c
@@ -85,7 +85,7 @@
     SZ((array)), 0, SZ((array)) - 1, SZ((array)) - 1, -1, NULL, NULL, NULL
 
 /* Common configuration table flags */
     SZ((array)), 0, SZ((array)) - 1, SZ((array)) - 1, -1, NULL, NULL, NULL
 
 /* Common configuration table flags */

-#define EFF_CFG (EFF_RDONLY | EFF_MEM | EFF_STATIC)
+#define EFF_CFG (EFF_PRIVATE | EFF_MEM | EFF_STATIC)

 
 struct empfile empfile[] = {
     /*
 
 struct empfile empfile[] = {
     /*


@@ -95,7 +95,7 @@ struct empfile empfile[] = {
      * bits of flags get their final value.
      * If flags & EFF_STATIC, the cache is mapped here, and members
      * cache, csize get their final value.
      * bits of flags get their final value.
      * If flags & EFF_STATIC, the cache is mapped here, and members
      * cache, csize get their final value.

-     * Members baseid, cids, fids and the EFF_MEM|EFF_RDONLY bits of
+     * Members baseid, cids, fids and the EFF_MEM|EFF_PRIVATE bits of

      * flags are initialized according the initial cache contents.
      * Member fd is initialized to -1.
      * Members init, postread, prewrite get initialized to NULL, but
      * flags are initialized according the initial cache contents.
      * Member fd is initialized to -1.
      * Members init, postread, prewrite get initialized to NULL, but