core/jni/android_database_CursorWindow.cpp

/*
 * Copyright (C) 2007 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.
 */

#undef LOG_TAG
#define LOG_TAG "CursorWindow"
#define LOG_NDEBUG 0

#include <inttypes.h>
#include <jni.h>
#include <nativehelper/JNIHelp.h>
#include <android_runtime/AndroidRuntime.h>

#include <utils/Log.h>
#include <utils/String8.h>
#include <utils/String16.h>
#include <utils/Unicode.h>

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <dirent.h>

#undef LOG_NDEBUG
#define LOG_NDEBUG 1

#include <androidfw/CursorWindow.h>
#include "android_os_Parcel.h"
#include "android_util_Binder.h"
#include "android_database_SQLiteCommon.h"

#include "core_jni_helpers.h"

namespace android {

static struct {
    jfieldID data;
    jfieldID sizeCopied;
} gCharArrayBufferClassInfo;

static jstring gEmptyString;

static void throwExceptionWithRowCol(JNIEnv* env, jint row, jint column) {
    String8 msg;
    msg.appendFormat("Couldn't read row %d, col %d from CursorWindow.  "
            "Make sure the Cursor is initialized correctly before accessing data from it.",
            row, column);
    jniThrowException(env, "java/lang/IllegalStateException", msg.string());
}

static void throwUnknownTypeException(JNIEnv * env, jint type) {
    String8 msg;
    msg.appendFormat("UNKNOWN type %d", type);
    jniThrowException(env, "java/lang/IllegalStateException", msg.string());
}

static int getFdCount() {
    char fdpath[PATH_MAX];
    int count = 0;
    snprintf(fdpath, PATH_MAX, "/proc/%d/fd", getpid());
    DIR *dir = opendir(fdpath);
    if (dir != NULL) {
        struct dirent *dirent;
        while ((dirent = readdir(dir))) {
            count++;
        }
        count -= 2; // discount "." and ".."
        closedir(dir);
    }
    return count;
}

static jlong nativeCreate(JNIEnv* env, jclass clazz, jstring nameObj, jint cursorWindowSize) {
    String8 name;
    const char* nameStr = env->GetStringUTFChars(nameObj, NULL);
    name.setTo(nameStr);
    env->ReleaseStringUTFChars(nameObj, nameStr);

    CursorWindow* window;
    status_t status = CursorWindow::create(name, cursorWindowSize, &window);
    if (status || !window) {
        jniThrowExceptionFmt(env,
                "android/database/CursorWindowAllocationException",
                "Could not allocate CursorWindow '%s' of size %d due to error %d.",
                name.string(), cursorWindowSize, status);
        return 0;
    }

    LOG_WINDOW("nativeInitializeEmpty: window = %p", window);
    return reinterpret_cast<jlong>(window);
}

static jlong nativeCreateFromParcel(JNIEnv* env, jclass clazz, jobject parcelObj) {
    Parcel* parcel = parcelForJavaObject(env, parcelObj);

    CursorWindow* window;
    status_t status = CursorWindow::createFromParcel(parcel, &window);
    if (status || !window) {
        jniThrowExceptionFmt(env,
                "android/database/CursorWindowAllocationException",
                "Could not create CursorWindow from Parcel due to error %d, process fd count=%d",
                status, getFdCount());
        return 0;
    }

    LOG_WINDOW("nativeInitializeFromBinder: numRows = %d, numColumns = %d, window = %p",
            window->getNumRows(), window->getNumColumns(), window);
    return reinterpret_cast<jlong>(window);
}

static void nativeDispose(JNIEnv* env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    if (window) {
        LOG_WINDOW("Closing window %p", window);
        delete window;
    }
}

static jstring nativeGetName(JNIEnv* env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    return env->NewStringUTF(window->name().string());
}

static void nativeWriteToParcel(JNIEnv * env, jclass clazz, jlong windowPtr,
        jobject parcelObj) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    Parcel* parcel = parcelForJavaObject(env, parcelObj);

    status_t status = window->writeToParcel(parcel);
    if (status) {
        String8 msg;
        msg.appendFormat("Could not write CursorWindow to Parcel due to error %d.", status);
        jniThrowRuntimeException(env, msg.string());
    }
}

static void nativeClear(JNIEnv * env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Clearing window %p", window);
    status_t status = window->clear();
    if (status) {
        LOG_WINDOW("Could not clear window. error=%d", status);
    }
}

static jint nativeGetNumRows(JNIEnv* env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    return window->getNumRows();
}

static jboolean nativeSetNumColumns(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint columnNum) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    status_t status = window->setNumColumns(columnNum);
    return status == OK;
}

static jboolean nativeAllocRow(JNIEnv* env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    status_t status = window->allocRow();
    return status == OK;
}

static void nativeFreeLastRow(JNIEnv* env, jclass clazz, jlong windowPtr) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    window->freeLastRow();
}

static jint nativeGetType(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("returning column type affinity for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        // FIXME: This is really broken but we have CTS tests that depend
        // on this legacy behavior.
        //throwExceptionWithRowCol(env, row, column);
        return CursorWindow::FIELD_TYPE_NULL;
    }
    return window->getFieldSlotType(fieldSlot);
}

static jbyteArray nativeGetBlob(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Getting blob for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        throwExceptionWithRowCol(env, row, column);
        return NULL;
    }

    int32_t type = window->getFieldSlotType(fieldSlot);
    if (type == CursorWindow::FIELD_TYPE_BLOB || type == CursorWindow::FIELD_TYPE_STRING) {
        size_t size;
        const void* value = window->getFieldSlotValueBlob(fieldSlot, &size);
        if (!value) {
            throw_sqlite3_exception(env, "Native could not read blob slot");
            return NULL;
        }
        jbyteArray byteArray = env->NewByteArray(size);
        if (!byteArray) {
            env->ExceptionClear();
            throw_sqlite3_exception(env, "Native could not create new byte[]");
            return NULL;
        }
        env->SetByteArrayRegion(byteArray, 0, size, static_cast<const jbyte*>(value));
        return byteArray;
    } else if (type == CursorWindow::FIELD_TYPE_INTEGER) {
        throw_sqlite3_exception(env, "INTEGER data in nativeGetBlob ");
    } else if (type == CursorWindow::FIELD_TYPE_FLOAT) {
        throw_sqlite3_exception(env, "FLOAT data in nativeGetBlob ");
    } else if (type == CursorWindow::FIELD_TYPE_NULL) {
        // do nothing
    } else {
        throwUnknownTypeException(env, type);
    }
    return NULL;
}

static jstring nativeGetString(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Getting string for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        throwExceptionWithRowCol(env, row, column);
        return NULL;
    }

    int32_t type = window->getFieldSlotType(fieldSlot);
    if (type == CursorWindow::FIELD_TYPE_STRING) {
        size_t sizeIncludingNull;
        const char* value = window->getFieldSlotValueString(fieldSlot, &sizeIncludingNull);
        if (!value) {
            throw_sqlite3_exception(env, "Native could not read string slot");
            return NULL;
        }
        if (sizeIncludingNull <= 1) {
            return gEmptyString;
        }
        // Convert to UTF-16 here instead of calling NewStringUTF.  NewStringUTF
        // doesn't like UTF-8 strings with high codepoints.  It actually expects
        // Modified UTF-8 with encoded surrogate pairs.
        String16 utf16(value, sizeIncludingNull - 1);
        return env->NewString(reinterpret_cast<const jchar*>(utf16.string()), utf16.size());
    } else if (type == CursorWindow::FIELD_TYPE_INTEGER) {
        int64_t value = window->getFieldSlotValueLong(fieldSlot);
        char buf[32];
        snprintf(buf, sizeof(buf), "%" PRId64, value);
        return env->NewStringUTF(buf);
    } else if (type == CursorWindow::FIELD_TYPE_FLOAT) {
        double value = window->getFieldSlotValueDouble(fieldSlot);
        char buf[32];
        snprintf(buf, sizeof(buf), "%g", value);
        return env->NewStringUTF(buf);
    } else if (type == CursorWindow::FIELD_TYPE_NULL) {
        return NULL;
    } else if (type == CursorWindow::FIELD_TYPE_BLOB) {
        throw_sqlite3_exception(env, "Unable to convert BLOB to string");
        return NULL;
    } else {
        throwUnknownTypeException(env, type);
        return NULL;
    }
}

static jcharArray allocCharArrayBuffer(JNIEnv* env, jobject bufferObj, size_t size) {
    jcharArray dataObj = jcharArray(env->GetObjectField(bufferObj,
            gCharArrayBufferClassInfo.data));
    if (dataObj && size) {
        jsize capacity = env->GetArrayLength(dataObj);
        if (size_t(capacity) < size) {
            env->DeleteLocalRef(dataObj);
            dataObj = NULL;
        }
    }
    if (!dataObj) {
        jsize capacity = size;
        if (capacity < 64) {
            capacity = 64;
        }
        dataObj = env->NewCharArray(capacity); // might throw OOM
        if (dataObj) {
            env->SetObjectField(bufferObj, gCharArrayBufferClassInfo.data, dataObj);
        }
    }
    return dataObj;
}

static void fillCharArrayBufferUTF(JNIEnv* env, jobject bufferObj,
        const char* str, size_t len) {
    ssize_t size = utf8_to_utf16_length(reinterpret_cast<const uint8_t*>(str), len);
    if (size < 0) {
        size = 0; // invalid UTF8 string
    }
    jcharArray dataObj = allocCharArrayBuffer(env, bufferObj, size);
    if (dataObj) {
        if (size) {
            jchar* data = static_cast<jchar*>(env->GetPrimitiveArrayCritical(dataObj, NULL));
            utf8_to_utf16_no_null_terminator(reinterpret_cast<const uint8_t*>(str), len,
                    reinterpret_cast<char16_t*>(data), (size_t) size);
            env->ReleasePrimitiveArrayCritical(dataObj, data, 0);
        }
        env->SetIntField(bufferObj, gCharArrayBufferClassInfo.sizeCopied, size);
    }
}

static void clearCharArrayBuffer(JNIEnv* env, jobject bufferObj) {
    jcharArray dataObj = allocCharArrayBuffer(env, bufferObj, 0);
    if (dataObj) {
        env->SetIntField(bufferObj, gCharArrayBufferClassInfo.sizeCopied, 0);
    }
}

static void nativeCopyStringToBuffer(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column, jobject bufferObj) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Copying string for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        throwExceptionWithRowCol(env, row, column);
        return;
    }

    int32_t type = window->getFieldSlotType(fieldSlot);
    if (type == CursorWindow::FIELD_TYPE_STRING) {
        size_t sizeIncludingNull;
        const char* value = window->getFieldSlotValueString(fieldSlot, &sizeIncludingNull);
        if (sizeIncludingNull > 1) {
            fillCharArrayBufferUTF(env, bufferObj, value, sizeIncludingNull - 1);
        } else {
            clearCharArrayBuffer(env, bufferObj);
        }
    } else if (type == CursorWindow::FIELD_TYPE_INTEGER) {
        int64_t value = window->getFieldSlotValueLong(fieldSlot);
        char buf[32];
        snprintf(buf, sizeof(buf), "%" PRId64, value);
        fillCharArrayBufferUTF(env, bufferObj, buf, strlen(buf));
    } else if (type == CursorWindow::FIELD_TYPE_FLOAT) {
        double value = window->getFieldSlotValueDouble(fieldSlot);
        char buf[32];
        snprintf(buf, sizeof(buf), "%g", value);
        fillCharArrayBufferUTF(env, bufferObj, buf, strlen(buf));
    } else if (type == CursorWindow::FIELD_TYPE_NULL) {
        clearCharArrayBuffer(env, bufferObj);
    } else if (type == CursorWindow::FIELD_TYPE_BLOB) {
        throw_sqlite3_exception(env, "Unable to convert BLOB to string");
    } else {
        throwUnknownTypeException(env, type);
    }
}

static jlong nativeGetLong(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Getting long for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        throwExceptionWithRowCol(env, row, column);
        return 0;
    }

    int32_t type = window->getFieldSlotType(fieldSlot);
    if (type == CursorWindow::FIELD_TYPE_INTEGER) {
        return window->getFieldSlotValueLong(fieldSlot);
    } else if (type == CursorWindow::FIELD_TYPE_STRING) {
        size_t sizeIncludingNull;
        const char* value = window->getFieldSlotValueString(fieldSlot, &sizeIncludingNull);
        return sizeIncludingNull > 1 ? strtoll(value, NULL, 0) : 0L;
    } else if (type == CursorWindow::FIELD_TYPE_FLOAT) {
        return jlong(window->getFieldSlotValueDouble(fieldSlot));
    } else if (type == CursorWindow::FIELD_TYPE_NULL) {
        return 0;
    } else if (type == CursorWindow::FIELD_TYPE_BLOB) {
        throw_sqlite3_exception(env, "Unable to convert BLOB to long");
        return 0;
    } else {
        throwUnknownTypeException(env, type);
        return 0;
    }
}

static jdouble nativeGetDouble(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    LOG_WINDOW("Getting double for %d,%d from %p", row, column, window);

    CursorWindow::FieldSlot* fieldSlot = window->getFieldSlot(row, column);
    if (!fieldSlot) {
        throwExceptionWithRowCol(env, row, column);
        return 0.0;
    }

    int32_t type = window->getFieldSlotType(fieldSlot);
    if (type == CursorWindow::FIELD_TYPE_FLOAT) {
        return window->getFieldSlotValueDouble(fieldSlot);
    } else if (type == CursorWindow::FIELD_TYPE_STRING) {
        size_t sizeIncludingNull;
        const char* value = window->getFieldSlotValueString(fieldSlot, &sizeIncludingNull);
        return sizeIncludingNull > 1 ? strtod(value, NULL) : 0.0;
    } else if (type == CursorWindow::FIELD_TYPE_INTEGER) {
        return jdouble(window->getFieldSlotValueLong(fieldSlot));
    } else if (type == CursorWindow::FIELD_TYPE_NULL) {
        return 0.0;
    } else if (type == CursorWindow::FIELD_TYPE_BLOB) {
        throw_sqlite3_exception(env, "Unable to convert BLOB to double");
        return 0.0;
    } else {
        throwUnknownTypeException(env, type);
        return 0.0;
    }
}

static jboolean nativePutBlob(JNIEnv* env, jclass clazz, jlong windowPtr,
        jbyteArray valueObj, jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    jsize len = env->GetArrayLength(valueObj);

    void* value = env->GetPrimitiveArrayCritical(valueObj, NULL);
    status_t status = window->putBlob(row, column, value, len);
    env->ReleasePrimitiveArrayCritical(valueObj, value, JNI_ABORT);

    if (status) {
        LOG_WINDOW("Failed to put blob. error=%d", status);
        return false;
    }

    LOG_WINDOW("%d,%d is BLOB with %u bytes", row, column, len);
    return true;
}

static jboolean nativePutString(JNIEnv* env, jclass clazz, jlong windowPtr,
        jstring valueObj, jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);

    size_t sizeIncludingNull = env->GetStringUTFLength(valueObj) + 1;
    const char* valueStr = env->GetStringUTFChars(valueObj, NULL);
    if (!valueStr) {
        LOG_WINDOW("value can't be transferred to UTFChars");
        return false;
    }
    status_t status = window->putString(row, column, valueStr, sizeIncludingNull);
    env->ReleaseStringUTFChars(valueObj, valueStr);

    if (status) {
        LOG_WINDOW("Failed to put string. error=%d", status);
        return false;
    }

    LOG_WINDOW("%d,%d is TEXT with %u bytes", row, column, sizeIncludingNull);
    return true;
}

static jboolean nativePutLong(JNIEnv* env, jclass clazz, jlong windowPtr,
        jlong value, jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    status_t status = window->putLong(row, column, value);

    if (status) {
        LOG_WINDOW("Failed to put long. error=%d", status);
        return false;
    }

    LOG_WINDOW("%d,%d is INTEGER 0x%016llx", row, column, value);
    return true;
}

static jboolean nativePutDouble(JNIEnv* env, jclass clazz, jlong windowPtr,
        jdouble value, jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    status_t status = window->putDouble(row, column, value);

    if (status) {
        LOG_WINDOW("Failed to put double. error=%d", status);
        return false;
    }

    LOG_WINDOW("%d,%d is FLOAT %lf", row, column, value);
    return true;
}

static jboolean nativePutNull(JNIEnv* env, jclass clazz, jlong windowPtr,
        jint row, jint column) {
    CursorWindow* window = reinterpret_cast<CursorWindow*>(windowPtr);
    status_t status = window->putNull(row, column);

    if (status) {
        LOG_WINDOW("Failed to put null. error=%d", status);
        return false;
    }

    LOG_WINDOW("%d,%d is NULL", row, column);
    return true;
}

static const JNINativeMethod sMethods[] =
{
    /* name, signature, funcPtr */
    { "nativeCreate", "(Ljava/lang/String;I)J",
            (void*)nativeCreate },
    { "nativeCreateFromParcel", "(Landroid/os/Parcel;)J",
            (void*)nativeCreateFromParcel },
    { "nativeDispose", "(J)V",
            (void*)nativeDispose },
    { "nativeWriteToParcel", "(JLandroid/os/Parcel;)V",
            (void*)nativeWriteToParcel },

    { "nativeGetName", "(J)Ljava/lang/String;",
            (void*)nativeGetName },
    { "nativeGetBlob", "(JII)[B",
            (void*)nativeGetBlob },
    { "nativeGetString", "(JII)Ljava/lang/String;",
            (void*)nativeGetString },
    { "nativeCopyStringToBuffer", "(JIILandroid/database/CharArrayBuffer;)V",
            (void*)nativeCopyStringToBuffer },
    { "nativePutBlob", "(J[BII)Z",
            (void*)nativePutBlob },
    { "nativePutString", "(JLjava/lang/String;II)Z",
            (void*)nativePutString },

    // ------- @FastNative below here ----------------------
    { "nativeClear", "(J)V",
            (void*)nativeClear },
    { "nativeGetNumRows", "(J)I",
            (void*)nativeGetNumRows },
    { "nativeSetNumColumns", "(JI)Z",
            (void*)nativeSetNumColumns },
    { "nativeAllocRow", "(J)Z",
            (void*)nativeAllocRow },
    { "nativeFreeLastRow", "(J)V",
            (void*)nativeFreeLastRow },
    { "nativeGetType", "(JII)I",
            (void*)nativeGetType },
    { "nativeGetLong", "(JII)J",
            (void*)nativeGetLong },
    { "nativeGetDouble", "(JII)D",
            (void*)nativeGetDouble },

    { "nativePutLong", "(JJII)Z",
            (void*)nativePutLong },
    { "nativePutDouble", "(JDII)Z",
            (void*)nativePutDouble },
    { "nativePutNull", "(JII)Z",
            (void*)nativePutNull },
};

int register_android_database_CursorWindow(JNIEnv* env)
{
    jclass clazz = FindClassOrDie(env, "android/database/CharArrayBuffer");

    gCharArrayBufferClassInfo.data = GetFieldIDOrDie(env, clazz, "data", "[C");
    gCharArrayBufferClassInfo.sizeCopied = GetFieldIDOrDie(env, clazz, "sizeCopied", "I");

    gEmptyString = MakeGlobalRefOrDie(env, env->NewStringUTF(""));

    return RegisterMethodsOrDie(env, "android/database/CursorWindow", sMethods, NELEM(sMethods));
}

} // namespace android