Add ashmem implementation for libjpeg decoder's backing store

Bug: 2791339

Change-Id: Ibfb48c0016ec5bdd8e8220e0479d88d5a2aaa1c1

3 files changed, 190 insertions, 1 deletions

diff --git a/Android.mk b/Android.mk
index 20f338a..9e1c42e 100644
--- a/Android.mk
+++ b/Android.mk
@@ -12,7 +12,17 @@ LOCAL_SRC_FILES := \
 	jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \
 	jfdctint.c jidctflt.c jidctred.c jquant1.c \
 	jquant2.c jutils.c jmemmgr.c \
-	jmem-android.c
+
+# use ashmem as libjpeg decoder's backing store
+LOCAL_CFLAGS += -DUSE_ANDROID_ASHMEM
+LOCAL_SRC_FILES += \
+	jmem-ashmem.c
+
+# the original android memory manager.
+# use sdcard as libjpeg decoder's backing store
+#LOCAL_SRC_FILES += \
+#	jmem-android.c
+
 
 # the assembler is only for the ARM version, don't break the Linux sim
 ifneq ($(TARGET_ARCH),arm)
@@ -37,4 +47,7 @@ LOCAL_CFLAGS += -DANDROID_TILE_BASED_DECODE
 
 LOCAL_MODULE:= libjpeg
 
+LOCAL_SHARED_LIBRARIES := \
+	libcutils
+
 include $(BUILD_SHARED_LIBRARY)
diff --git a/jmem-ashmem.c b/jmem-ashmem.c
new file mode 100644
index 0000000..3a17b02
--- /dev/null
+++ b/jmem-ashmem.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2007-2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jmemsys.h"		/* import the system-dependent declarations */
+
+#include <cutils/ashmem.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#ifndef HAVE_STDLIB_H		/* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+#endif
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+  return (void *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+  free(object);
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+  return (void FAR *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+  free(object);
+}
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM		/* so can override from makefile */
+#define DEFAULT_MAX_MEM		10000000L /* default: ten megabyte */
+#endif
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+		    long max_bytes_needed, long already_allocated)
+{
+  return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed.  You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+METHODDEF(void)
+read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+		    void FAR * buffer_address,
+		    long file_offset, long byte_count)
+{
+  memmove(buffer_address, info->addr + file_offset, byte_count);
+}
+
+
+METHODDEF(void)
+write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+		     void FAR * buffer_address,
+		     long file_offset, long byte_count)
+{
+  memmove(info->addr + file_offset, buffer_address, byte_count);
+}
+
+
+METHODDEF(void)
+close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+  munmap(info->addr, info->size);
+  close(info->temp_file);
+}
+
+LOCAL(int)
+get_ashmem(backing_store_ptr info, long total_bytes_needed)
+{
+  char path[1024];
+  snprintf(path, 1023, "%d.tmp.ashmem", getpid());
+  int fd = ashmem_create_region(path, total_bytes_needed);
+  if (fd == -1) {
+      return -1;
+  }
+  int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
+  if (err) {
+      return -1;
+  }
+  info->addr = mmap(NULL, total_bytes_needed, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+  info->size = total_bytes_needed;
+  info->temp_file = fd;
+  return fd;
+}
+
+/*
+ * Initial opening of a backing-store object.
+ * This version uses ashmem to get a shared memory of total-bytes_needed.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+			 long total_bytes_needed)
+{
+  if (get_ashmem(info, total_bytes_needed) == -1)
+    ERREXITS(cinfo, JERR_TFILE_CREATE, "");
+  info->read_backing_store = read_backing_store;
+  info->write_backing_store = write_backing_store;
+  info->close_backing_store = close_backing_store;
+}
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+  return DEFAULT_MAX_MEM;	/* default for max_memory_to_use */
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+  /* no work */
+}
diff --git a/jmemsys.h b/jmemsys.h
index 6c3c6d3..2ed1c63 100644
--- a/jmemsys.h
+++ b/jmemsys.h
@@ -161,11 +161,17 @@ typedef struct backing_store_struct {
   FSSpec tempSpec;		/* the FSSpec for the temp file */
   char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
 #else
+#ifdef USE_ANDROID_ASHMEM
+  short temp_file;		/* file reference number to temp file */
+  unsigned char* addr;  /* the memory address mapped to ashmem */
+  long size;            /* the requested ashmem size */
+#else
   /* For a typical implementation with temp files, we need: */
   FILE * temp_file;		/* stdio reference to temp file */
   char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */
 #endif
 #endif
+#endif
 } backing_store_info;